Monday, February 3, 2020

Health care professional inerview Essay Example | Topics and Well Written Essays - 500 words

Health care professional inerview - Essay Example These tasks are done both in the hospital setup, at the home of patients, within the community schools as well as in industries. Community paramedics thus deliver services to emergencies with the main objectives of prevention of health harm. Paramedics offer their services round the clock to address the health concern of people in the community. This work mainly targets those whose capacity is impaired and the vulnerable members with the intention of achieving a universal coverage of health. Vickie L. Martin elaborated that a typical day for a community paramedics is one parameter that is difficult to predict. She states that a paramedic officer is an individual trained to be prepared all the time for an emergency whether on duty or off duty. A typical day for a paramedic officer can begin by responding to an emergency entailing fire outbreak or flood. Paramedics are responsible for the resuscitation of the victims of the crisis, offering first aid services and transferring those in need of special health services to a health care facility. The duty of a paramedic can take unpredictable duration in an emergency sport. Nevertheless, community paramedics are trained to offer their services within the shortest time possible as a way of allowing time to respond to other situations. The day is equally spent reporting emergency services to the relevant authority as well as collaborating with other health care workers to deliver services in hospital and community setting. A community paramedic works in a multivariate practice setting, these include in the community, giving services to the community. A professional in this field can equally practice in a health facility as well as in the research institutions. Working in an environment that demand speed in action, community paramedics work with the ambulance services as well as with the emergency airlift services for quick delivery of health care needs. According to Vickie L. Martin, the requirements

Sunday, January 26, 2020

The Potential Of Wind Assisted Ship Propulsion Engineering Essay

The Potential Of Wind Assisted Ship Propulsion Engineering Essay Wind is present all around the world, and in some places with abundant energy density. Wind had been extensively used in the past, for mechanical power in addition to transportation (J.F. Manwell and J.G. McGowan, A.L. Rogers (2009)).Wind energy has evolved into one of the most practical, cost-effective and both environmentally and technically attractive, of all the renewable energy options in the world. So the wind energy has a lot of potential at sea for assisting in ships propulsion. Wind is the cheapest, most powerful, and greenest source of energy on the high seas. The accelerating fuel costs over the last decade have led to growing interest in the application of wind assistance for ship propulsion and reduce fossil fuel consumption. Using wind energy for propulsion of ships in sea is in fact one of mankinds oldest ocean-going technologies. In one-way or another, with modern advances in ship design and propulsion the use of wind energy was almost forgotten Sail systems were the dominant form of propulsion until the 19th century (http://en.wikipedia.org/wiki/Marine_propulsion) Astrophysicist Carl again writes, for example, that: the consequences of scientific illiteracy are far more dangerous in our time than in any that has come before. Its perilous and foolhardy for the average citizen to remain ignorant about global warming, say, or ozone depletion, air pollution, toxic and radioactive wastes, acid rain, topsoil erosion, tropical deforestation, exponential growthà ¢Ã¢â€š ¬Ã‚ ¦.How can we affect national policyà ¢Ã¢â€š ¬Ã‚ ¦ if we dont under stand the underlying issues? Aim and Objectives: The main of the project is to analysis into the potential of Wind Assisted Ship Propulsion (WASP) and its application into the modern day shipping. WASP systems will be explained, analysed by showing its benefits and drawbacks. The applications and possible benefits of the use of the WASP will also be investigated showing all the relevant factors that are affected by the use of WASP. The key objectives are summarized as: Research into present and evolution of WASP systems, Potential of present WASP system and their applications. Advantages and future development of WASP systems Discussion of economic and environmental factors Analysis into the use of alternative energy sources at sea. Evaluation of WASP by application to a case study Critical analyse into all findings to produce a logical and well founded conclusion. EXISTING WASP SYSTEMS: The following are the remaining WASP Systems in use at present in the sea Aerofoil(Wing-Sail) Flettner Rotor Rig Soft Sail Towing Kites (Skysails) Wind Turbine (Skysails) Aerofoil (Wing-Sail): This form of marine propulsion works in the similar way as an aeroplane wing, producing pressure differences between opposite sides which create a force , supported by central mast. The trust provided by the solid structures of the sail is more with less drag than conventional sails. This technology came into wide development in 1980s by Japanese and still some vessels use this technology nowadays with research into the application of such systems proceeding. Various research is been carried out and one of the example using this aerofoil concept is this ship model which is called the ecoliner. It is a type of cargo vessel which propels by using combination of high-tech sail and engine power. This combined feature, make it possible to work like a normal cargo ship with similar service of speed, freight price and other factors. Using this ecoliners , as ocean transports will decrease the pollution emissions to 50% of the ship. MV Ashington vessel is a bulk carrier which has auxiliary propulsion with the use aerodynamic wing sail. (http://www.shipspotting.com/gallery/photo.php?lid=823976) A computer controlled wingsail fitted to the 6,500 dwt dry cargo ship mv Ashington resulted in a fuel savings average of 8% and, under favourable circumstances, of up to 20%. (htt p://www.maritimejournal.com/features101/power-and-propulsion/wingsail_ready_for_small_commercial_vessels) The wing-sail have two significant drawbacks which are considered. First one is that the moments coupled with the lift forces which produce the propulsion also can create a large aerodynamic drag force which acts as a huge drawback when sailing directly into a head wind(Clayton, 1987).Rigid sails then usually themselves into the wind direction when no force can be created while some design allow the surface to be folded using hydraulic controls such that the direction can be controlled. In general wing-sails have a high lift coefficient compared to soft sails which will be discussed in further topics. This means this system has more advantage over the other conventional sails even though initial investment in the system will be high. Various designs now incorporate a frame with a material surface to keep the minimum weight. Flettner Rotor Rig: Flettner rotors consist of cylinders which are of spinning type and tall mounted onto the vessels deck. The vessel is set in motion by using the Magnus effect. The Magnus effect is produced whenever pressure difference occurring around spinning object. This concept was done by researcher Anton Flettner, a German naval architect. Later researchers conducted experimenting into its operation in 1980 when Saudi oil crisis happened. But this system never overtook the diesel engine usage. However in the 1920s Fletner rotor operated in sea for a quiet a long year proving reliable form of wind propulsion. To understand this system works, an understanding of the Magnus effect is necessary. The Magnus effect or force happens when there is a pressure difference around a spinning object. Because of this change in boundary later around this object happens, a lift force is generated in direct propulsion to the acceleration it imparts on the air streaming by (Seufert, 1983). This lift force happens due to Bernoullis principle; this use of the principle is highly effective and is described as practicable. Soft Sail: Soft Sail system consists of two main types, the modern square rig and the fore and aft rig. The square rig is the most efficient running rig and useful to longer routes with more constant and foreseeable winds.Fore and aft rig type is suitable to short routes, where the wind speed and direction be unlike. In modern day shipping the soft sails is not used, because of its large propulsion of deck space and needs constant manning. The reason for this is because the other types of sailing systems are more effective and efficient compared to these soft sails. The sky sail lakes large portion of deck space and always need constant manning. With deck space is considered more important for carrying cargos in present shipping world, it makes less effective in use and outweighs the advantages of any soft sail systems. The future of ship propulsion may consider this soft sail with combining with other types of propulsion to take advantages and use it in a efficient way. However there are some smaller vessels like fishing boats still depend on soft sails as an auxiliary propulsion force and the uses of soft sail are important in this fishing boats Towing Kites (Skysails): Towing Kites function on same basis as several conventional kite arrangements used on such things as Paragliding and kite boarding, etc. the propulsion of the vessel is assisted by the kite which harness the energy from wind. Since wind-conditions are not always sufficient, the Skysails system is designed to function as a supplementary power source, in addition to the ships engine. Skysail consists of a towing kite, a control system, a launch and recovery system and a wind-optimized routing system. The Para foil kite is constructed out of  high-strength, weatherproof textiles, and  is designed in such a way that it can achieve optimal aerodynamic efficiency at any wind speed. The steering system operates automatically and is composed of the control pod and the control system. The towing kite and the towing rope are linked by the control pod. Much like autopilot systems in airplanes, the Skysails sensors collect data that is processed by the systems software, which sends control orders accordingly. The launch and recovery system is responsible for automatically recovering and launching  the towing kite, control pod and towing rope. The kite is attached at only one point to the launch and recovery mast, enabling high manoeuvrability. A telescopic mast lifts the towing kite  during its launch. The wind unfolds the kite to its full size while the reef system launches the reef ropes. While the towing kite is decoupled from the launch and recovery mast, the towing rope is released. The power transmission system consists of a  towing rope, a force transmission point (tow point), and winch, and is responsible for transferring the tractive force from the kite to the ship.  The mounting system ensures that the towing kites force is aligned ideally to suit the winds direction. The routing system is composed of  a weather forecasting performance calculator, which processes the weather forecasting data and of a decision-making model, which calculates the optimal route following priorities set by the ships owner. Finally, the routing system has a route recommendation feature, which translates the information into a series of waypoints read by the shipmaster. The SkySails system also improves the ships safety and performance on water as it damps the waves so that the ship suffers from less slamming and torsion forces. In addition, as a result of smoother sailing, the ships life is extended. A short video of a ship equipped with the SkySails system is available (http://www.maplesoft.com/company/casestudies/skysails.aspx) The steering system of skysail operates automatically meaning that there is no input need via crew, just observation. The skysail system will have a control pod situated on the high strength towing rope and the kite. This pod changes the profile of the kite such that it ultimately controls its flyting path in line with ship needed direction. Wind-Turbine: Wind turbines are widely used in land; however it has not yet been applied on at large scale in the shipping industry. Wind turbines at sea could perform two functions as electricity generation and in aid of propulsion. The drawback using wind turbine is it will be ineffective at no wind and counterproductive at high wind conditions.many smaller vessels have used wind turbines directly connected through gearbox to the propeller. But large vessels need large size machine to drive the generators which makes complex engineering to make it work stable. Also this system will need more time to get fitted, assembled such that it means it will be suitable for future vessels. APPLICATION OF WASP SYSTEMS: The use and development of WASP systems in the modern day shipping should be considered to make an adequate conclusion .At present WASP system are at very small percentage of the global marine transportation industry. The different types of systems are already present in use various ships and also in small vessels such that it makes easy to have a very good potential in upcoming years since the price of fossil fuels hikes and also they pollute the air which made global impact to cut the harmful exists of these pollution.by looking at the advantages and the usefulness of WASP systems and its drawbacks, various factors related to it can be analysed. The further topics will discuss about the advantages and applications of these systems. POTENTIAL OF PRESENT WASP IN PLACE: WASP is already in place for long ago in small vessels like boats in fishing industry. Currently WASP is present in less in global marine industry but its still considered as notable, potential system to avoid fossil fuels.by analysis the various factors and cases, understanding can be done greater. Oil crisis happened in 1970s and 1980s , the Japanese were very conscious and tried to look into alternative to the field of ship propulsion and some 17 sail- assisted tankers were produced with all having similar design. The first vessel with name Shin-Aitoku-Maru (DWT: 1600), in 1980 reached 11knots speed when the sea and ship conditions were good. These sails travelled in sea during that oil crisis but later the oil prices dropped down again .this made the diesel engines to overcome those sails and the marine industry discarded to use the systems .however the environmental concern arrived in 2010 regarding water and air pollution due to the fossil fuel .this play a massive role to change the world to look into alternative energy sources that can be used in sea and imposing rules and regulations on various pollution factors. APPLICATION OF WASP: The application of WASP systems are vastly used in fishing industry in smaller vessels. Many American and European boats have small auxiliary soft sails but they are used rarely. Large commercial fishing vessels does not utilise wind at all, since it would be impractical most often. They increase work load on crew with others factors including cost of the equipment and less knowledge to use the system of WASP will make it difficult to use it. It can be seen in statistics that WASP could be used in fishing fleet to a greater extent that actually works. By looking at historical research, wind has been used ad earlier way of propulsion when no engines exists. The transaction from the main form of propulsion changing from wing to coal- fire propulsion units took place so quick over a time spam of 30 years. However increase in price of fuel and pressure to reduce fuel consumption. Skysails are used by Wesselss Sipping Company on three vessels where some good results have ben obtained. WHERE WASP MAY BE APPLIED: Although climate change has occurred since the creation of the Earth today it represents a setback to a society that grew in the last two centuries to over 7 billion with an associated energy demand based primarily on the consumption of fossil fuels. The global population is expected to peak at 9.2 billion around 2075, while social development is desired to continue.so its important that WASP could be used in various ships propulsion. WASP may not be a good solution in making all vessels more efficient and reduce fuel consumption. But some vessels use the benefit of this systems.in recent years Ultra Large Crude Carriers (ULC) and Very Large Crude Carriers (VLC) dominates the transport of crude oil and the benefits of WASP on such kind of carriers are hard to be seen in practice. But smaller carriers may benefit from WASP technology and vessels which run on lower speed can use this type of propulsion to reduce fuel consumption. For example, steam coal and iron ore are usually stored on a very large scale before the resource is even utilised. In that case the vessels can carry them with the use of WASP which can produce 11-13 knots speed and its practicable. FACTORS One of the weapons used by all vessels, the WASP combat is essentially highly advanced missiles that contain a variety of sub munitions. The computer that controls each one is also able to analyse tactical situations and plot the best path to achieve your goal and ensure success. The WASP has a maximum acceleration of 20g when using standard fusion fuel. This acceleration and speeds allows the WASP conditions for manoeuvre and more power. This speed advantage and acceleration allows you to run more. In addition to attacking enemy ships or space stations, WASP combat can also be used as a defines drones. In this mission profile, WASP can also be used as thermonuclear warheads or anti-matter ahead of the enemy. The health and economic impacts In this area, we are only beginning to understand the true extent of the consequences on utilization of WASP systems. Intuitively there is an accumulation of pollutants through the food chain and possibly in our drinking water supplies. But, according to Technical Document Management Measures National Pollution Control Environmental Protection Agencies, published in November 2001, petrol, oil, diesel fuel, and batteries and acidic cleaning compounds, and solvents involved in the maintenance of the boats ( as methylene chloride, tetrachloroethene, trichloroethene, and trichlorethylene) trickle in lakes, rivers and coastal areas, and many of these pollutants, particularly some of the heavy metals are attached to sediments and are eventually found in the food chain through either plankton or other organisms and then concentrated through the food chain, being a major environmental threat as well as a big human health problem when it comes to fish consumption. The high speed of supply and refuelling system used by WASP does not mask the problems caused by liquid spills and toxic gases; rather, it completely solves the problems. Industry There are economic consequences for the marine industry. The short-term impacts that cause direct financial costs are cleaning and punitive actions associated with them. Over time, the waters are much polluted, further legislative measures are introduced. Clean water is essential for multibillion dollar industry. Environment Supply system by WASP system is a high-speed refilling helps the environment in many respects, eliminating damage caused by other products refuelling. This product eliminates the smoke harmful gas that gives off the oil, polluting the air. It eliminates the greenhouse gases that pollute the earth and our ozone layer. This system prevents leaks that harm the soil. There was never a supply system created before can eliminate all kinds of damage, and that works without causing pollution. The high speed of supply and refuelling system using the WASP does not mask the problems caused by liquid spills and toxic gases, however, solve them by complete. Most of the damage caused by the emission engines and oil leaks comes from petroleum. Small leaks, despite being isolated events tend to occur every day around the world, they are, gallons of oil pollution in our waters. A small fuel leak affects a disproportionate amount of water on the surface of the ocean. In the UK the legal limit leaking oil and one drop of oil for every 2 litres of water in a proportion of 15mg per litre. Therefore, a single litre of oil can contaminate one million litres of water. And this is a chronic problem to be solved, and the reaction of sunlight, the chemicals become infinitely more toxic, and prolonged exposure affects thousands of fish species and a myriad of creatures such as shellfish, marine plants and damage as algae and their reproduction when exposed to oil. And the old trick of using soap or detergents to make the brightness disappear, is not only illegal, but it only makes pollution worse, and eventually adding surfactants to the mixture, whic h attach to the gills of fish and destroy their ability to breathe. The effect is catastrophic. And, as if that were not enough, the increase in population drives the development of the industry, and a lot of pressure on the marine environment. The impact on marine life inevitably leads to an impact on human health. WASP Systems are specialized in projects for supply, installation and commissioning of water systems and wastewater treatment systems, gray water recycling, along with some simple write-downs and innovative energy systems. The system creates a vacuum seal ventilating, and dramatically reduces the incidence of unintended leakage of gas that would normally escape to the atmosphere. The main advantage of the invention is that it allows the filling very quickly, which will significantly reduce operating costs for operators of vessels and facilities loading terminals. Applications for the WASP system will focus initially on three distinct segments in the market within the maritime industry: nautical recreation, navigation and commercial refuelling (as tugs, barges, ferries and commercial vessels), and loading of liquid cargo from ships that cross oceans. The deployment of this system in the world will eliminate millions of tons of harmful particles of gas to the atmosphere, and prevent millions of gallons of fuel from spreading into watercourses .freighters with this product, which is able to increase the delivery time cargo 100% and thus may reduce the time spent in each vessel terminals. We can shorten the terminal for vessels which reduces the rate per ton of whole load of liquid therefore increase the amount of deliveries for all vessels. We can reduce the waiting time for vessels which reduces the rate per ton of whole load of liquid therefore increase the amount of deliveries to all ships refuelling and increased how it works at high speeds. Our product also eliminates many greenhouse gases and gases hazardous to health that are associated with refuelling which in turn becomes safer for everyone to use our product to refuel. Currently we are working together this time with a major oil company and help them in their oils movement worldwide. 6.2 Economic factors Economic factors in the application of WASP freighters These ships can perform rapid sustained combat operations at sea as a centrepiece strategy. To carry out its core mission, WASP has a support system that synchronizes the simultaneous horizontal and vertical flow of cargo and vehicles throughout the ship. The ship propulsion can generate a total of 400 tons of steam per hour. If the energy of the two boilers were converted into electrical current could power a city of 160,000 inhabitants. Electric generators aboard a ship can provide more than 16,000 kilowatts of energy. Two stations provide a capacity of 450,000 litres to 200,000 litres of water per day supply. Chapter 5: Case Study 5.1: MS Beluga Skysails MS Beluga Skysails with its computer-controlled kite (top right corner) One of the latest innovations in the heavy cargo ship which increases fuel prices has been a return to wind power. The MS Beluga SkySails is a heavy carrier that uses a towing kite system as part of its propulsion systems. The ship was launched and followed early sea trials in the North Sea in January 2008, the vessel embarked on its maiden voyage from Bremerhaven, Columbuskaje to Guanta, Venezuela. On route, the efficiency of the system was applicable in winds of up to force five for 8 hours a day. The system was hailed as a success, with calculated savings of up to 2.5t of fuel/$1,000 a day. With larger sails of 600m ², fuel savings can get up to 35%, possible. CONSTRUCTION The system has been developed by SkySails SkySails GmbH and Co. KG. The Beluga SkySails was equipped to navigate with a candle paraglider 160m  ². The area of à ¢Ã¢â€š ¬Ã¢â‚¬ ¹Ãƒ ¢Ã¢â€š ¬Ã¢â‚¬ ¹the kite can be increased to 320m ². A pipe controlled by computer, is connected to the ship by a system of rope. The system can control the kite at altitudes between 100m and 500m to maximize the benefit of the wind. With oil prices so high, a cargo ship 87m average could save about à ¢Ã¢â‚¬Å¡Ã‚ ¬ 300,000 a year. The system can potentially be adjusted to any ship. The overall reduction of carbon dioxide transport arrives at an estimate of considerable million tons per year. The BBC said there is something magical, a giant cargo ship being pulled on its way to the sea with ten thousand tons of metal, and with the sun shining giant masts. But there is something even more magical about the MS Beluga SkySails. On the face of it, this ship leading, for example, parts of a production line of wood to Venezuela looks like any other cargo ship. MS Beluga SkySails believes its fuel bill will be cut by  £ 800 ($ 1,560) a day. We can demonstrate that it is possible to combine economy and ecology, says Verena Frank of Beluga Shipping, and explains, Economy, because you can reduce consumption and fuel costs and, moreover, contribute to ecology, reducing emissions carbon dioxide. the kite is controlled by computers. a computer helps to make it fly, and maximize the power it produces, the other computer adjusts the direction of the kite. If the project is successful, we expect to see kites even higher very soon sum up to 5,000 square feet in size, pulling ships ac ross the seas and oceans. Graphic Steve Rosenberg explains, See how the ship kite works: of all the CO2 that is pumped into the atmosphere today, 4% comes from ships. Thats more than the aviation industry, mainly because 90% of world trade is done by sea. The MS Beluga SkySails believes it has the solution environmentally, with a mission to transform the green oceans. Once the ship reaches the open sea, reveals a new weapon in the fight against global warming: a kite. The 160m2 kite is hoisted on a mast and for half an hour or so, he stands there at the top of the mast, not making a big thing. The wind and certainly a wonderful thing, because it only needs a bit of wind to make everything else work. Half an hour later, however, the wind makes the kite start to fly hundreds of feet in the air and helping to pull the ship. The paragliding and synonym of power to the engines of the ship, so you can work on reduced power: which means less carbon emissions. It also means lower bills in fuel costs. With the price of trans portation fuel that has doubled in the past two years, paragliding promises great savings. How the Ship-Parrot The kite helps reduce annual fuel costs 10-35%. Fuel economy also means fewer carbon emissions harmful to the atmosphere. The large towing kite resembles a glider and is shaped like an airplane wing, so you can take advantage of different wind directions. The kite operates at 100-300m above the surface much larger than a normal sailing boat where winds are stronger and more stable. The kite can be used in winds of 12-74 km / h (or 7 to 40 knots). The Technology Skysail Graphic References: Tom Schueneman, MS Beluga SkySails Completes Her Maiden Voyage (February 6th, 2008) http://www.ship-technology.com/projects/msbelugaskysails/ Steve Rosenberg, BBC News, Bremerhaven, northern Germany, Gone with the wind on kite ship (September, 2012) http://news.bbc.co.uk/1/hi/world/europe/7205217.stm

Saturday, January 18, 2020

The Future of Iptv and Ip-Video

ECE 6613: Broadband Access Networks The Future of IPTV and IP-Video Ji Hwan Kim Georgia Institute of Technology 325050 Georgia Tech Station Atlanta, GA 30332 Abstract— This paper describes the various IPTV architectures and components, which enables large-scale integration of current and future IPTV network. IPTV technologies are transforming how we perceive TV services today and global television industry as whole. However, there is pressing need for improvement on IPTV side to meet the Quality of Experience that is equal to or better than traditional TV services.In recent years, we have seen tremendous growth in Information Technology industry with the emergence of smart phone. Various new technologies are in its development to meet the demand of higher data rate, reliable data transfer, and readily available resources with distributed cloud servers to improve quality of service to the customers. With growing number of smart phone users, IPTV service has become ever more pop ular in telecommunication companies to provide streaming videos through the different new infrastructures.The biggest competitors in IPTV service in the U. S. are Verizon FioS (FTTP) and AT&T U-verse (FTTN) providing triple-play bundle service to the customer. In this paper, we are going to discuss IPTV service architecture difference of Verizon FiOS, AT&T U-verse, Cable Company, and Netflix as well as current IPTV research and development to increase quality of experience through multicast and cloud computing. Also we will analyze some of the emerging IPTV application in the future. Key Words — Internet Protocol Television (IPTV), Verizon FiOS, AT&T U-verse, MulticastIntroduction Today’s IPTV services IPTV technologies are transforming how we perceive TV services today and global television industry as whole. It is a collection of modern technologies in computing, networking, and storage combined to deliver high quality television contents through IP network. It is be coming a platform which changing how we access information and entertainment. In recent years, we have seen tremendous growth in video and networking technologies with the emergence of smart phone.Various new technologies are in its development to meet the demand of higher data rate, reliable data transfer, and readily available resources, distributed cloud servers, to improve quality of service to the customers. The figure below [1] is an example of IPTV broadband network inside a home. [pic] Fig. 1. Diagram of IPTV Broadband Network Inside Home. With IPTV service, video contents are not only limited to the TV but can utilize in multiple platforms to enjoy video content anywhere, anytime, and anydevice.IPTV alter the way the customer consume video content like personal video recorders have done and lets customer have complete control of their entertainment experience to a next level. [pic] Fig. 2. U. S. Multichannel Video Subscriber Census Above is a figure of U. S. Multichannel Vi deo Subscriber Census by SNL Kagan [2]. In 2011, the cable industry lost 1. 8 million video subscribers whereas IPTV providers gained 1. 6 million. This shows that IPTV industry is gaining market share on video content provider and it is expected to grow even more.Cable TV delivers entire line-up of broadcast content channels all the time which requires huge amount of bandwidth being delivered all the time into the home and cable companies are moving toward IPTV delivery services to reduce bandwidth on their infrastructure. IPTV architecture is very different in that it only delivers the single channel that is requested by the consumer’s individual TV. Therefore, IPTV architecture can greatly reduce bandwidth by only providing specific request from the consumer at any given time [4]. [pic] Fig. 3.Expected Growth in IPTV subscribers. However, there is pressing need for improvement on IPTV side to meet the Quality of Experience that is equal to or better than traditional TV ser vices. To provide great quality of experience in IPTV requires almost no packet loss, delay variation of 200ms, and delivery of no more than one perceivable error during a two-hour movie. This constrains and requirements puts heavy burden on service provider to provide reliable and lossless IPTV to customers and requires video admission control. The paper is outlined as follows.In Section II, we overview the different IPTV system and architecture exist today and how service providers are planning to improve their IPTV infrastructure. In Section III we will discuss the multicast protocol in depth and current research from Cisco to deliver IPTV service with multicast protocol. In Section V, we will discuss some of the potential future application that can be seen in near future with IPTV service. IPTV System and architecture IPTV networks generate their video contents for transmission using many clustered components collectively called headends.There are three common types of IPTV hea dends to meet national, regional and local content distribution requirements. Super Headends (SHE) receives and digests content on the national level typically from satellites. After processing and encoding, the SHEs distribute the national content to video hub offices (VHO) over a core IP/MPLS network. VHOs aggregate national, regional, and local content with the on-demand services, and serve metropolitan areas with a population of between 100,000 to 500,000 homes.VHOs are connected to video switching offices (VSO) over metro aggregation networks. VSOs distributed the IPTV streams to the customer premises over access network. The IPTV architecture is shown in Figure. 4. [pic] Fig. 4. End-to-End IPTV Network Architecture. The most conventional transport technique for IPTV is to multicast UDP/IP packets with MPEG-2 video compression scheme. The newer standard video architectures use RTP protocol which can provide error repair and stream monitoring unlike UDP protocol.IPTV service hav e slower channel change time compare to CATV service provider since all the TV channels are broadcasted simultaneously whereas IPTV needs to request certain channel from the provider. IPTV zapping time is affected by several factors such as Internet Group Management Protocol (IGMP) signaling delay of leaving and joining multicast group, MPEG decoding delay, program specific information (PSI) including program association table (PAT) and program map table (PMT) acquisition delay, random access point (RAP) delay, conditional access system (CAS) key acquisition delay, and de-jittering buffer delay in the STB [4].More detail of video admission control in IPTV multicast protocol will be discussed in Section III. IPTV service over a packet-switched network demands near zero packet loss and limited jitter. Thus, it is often necessary to enforce traffic management and admission control in IPTV network by sufficient provisioning and resource allocation [4]. More detail on resource allocation through retransmission server to improve IPTV will be discussed in Section III. Telco companies are embracing the IPTV technology since this will open up huge market share with Cable TV companies.Telco companies have been delivering packet-based IP traffic over their xDSL technology for many years and utilizing their existing technology to move to IPTV is a natural choice for them. However, there are great roadblocks to deploy IPTV over DSL which primarily concerned with quality of experience that is equal or better than traditional CATV. Below is the figure of IPTV infrastructure for Telco companies [1]. [pic] Fig. 5. Telco End-to-End IPTV Network Architecture. The primary difference in Telco companies’ architecture can be seen in red cloud shown in Fig. 5.Digital subscriber line access multiplexer (DSLAM) is located in environmentally controlled vaults or huts. It is also called video ready access devices (VRAD), which is placed on lawns or easements or a common space in a partment building. DSLAM often serves 100 to 200 residential gateways (RGs) that are attached to the outside of a residence and various techniques are used to transport signal between DSLAM and RG. Very high-bit-rate DSL (VDSL) for copper and broadband passive optical network (BPON) and gigabit PON (GPON) for giber transport. This metro access segment uses a hub-and-spoke architecture [5].Cable companies have been utilizing Hybrid fiber coaxial (HFC), combine optical fibers and coaxial cables, network since early 1990s to provide broadband internet access over existing cable TV system and its been employed this protocol globally and Data Over Cable Service Interface Specification (DOCSIS) is the international standard for developing equipment for HFC networks. Cable IPTV architecture is able to evolve from the traditional CATV with simple changes by adding few more components: cable modem (CM), cable modem termination system (CMTS), and a PacketCable Multimedia (PCMM).The cable comp anies’ architecture is shown in the figure below. [pic] Fig. 6. Cable Company Network Architecture. The CMTS and CM can provide a bidirectional IP over DOCSIS transport in the HFC network. CMTS can provide media access control (MAC) and physical protocol layer (PHY) in a single device by integrate with DOCSIS however, cable industry is moving toward a modular CMTS (M-CMTS). M-CMTS separates MAC and PHY layers to improve the scalability of DOCSIS transport.The CMTS manages DOCSIS QAM switching and provides QoS over the DOCSIS channel as well as manages residential CMs by dynamically load-balancing CMs among DOCSIS downstream channels to optimize traffic flow. PCMM policy server in DOCSIS networks defines admission control QoS policies by using session managers to request and reserve bandwidth for CMTS to enforce these QoS policies. A. Verizon Fios In 2004, Verizon began deployment of its Fiber to the Premises (FTTP) access network. The initial deployment used the ITU-T G. 983 BPON standard and in 2007, Verizon began using equipment with the ITU-T G. 84 G-PON standard. Fig. 6 below is Verizon’s BPON FTTP architecture diagram describing the connection between Optical Line Terminal (OLT) and Optical Network Terminal (ONT). OLT provides interface between Core network with voice, data, and video signals and Erbium Doped Fiber Amplifier (EDFA) boosts the [pic] Fig. 6. Verizon BPON FTTP architecture optical video signal. ONT performs the optical to electrical signal conversion and provide the data, voice, and video service to the subscriber. Wavelength division multiplexer (WDM) combines the three wavelengths onto a single fiber for transmission to the premises. 310nm wavelength is used for upstream traffic and for downstream, 1550nm (broadcast video) and 1490nm (data and voice) are being utilized. Fiber Distribution Hub (FDH) cabinet contains 1Ãâ€"32 passive optical splitters. Each subscriber is connected to a dedicated fiber between FHD and the premis es. BPON delivers 622 Mbps downstream and 155 Mbps upstream per PON for voice and data through ATM. FiOS provide over 600 channels between 50 to 870 MHz RF signal transmitted over the 1550nm wavelength. [pic] Fig. 7. Verizon FiOS RF spectrumGPON physical architecture is same as BPON however it provides significant improvements over BPON in bandwidth. GPON can provide 2. 5 Gbps downstream and 1. 2 Gbps upstream for data and voice and in addition, GPON have different transport by implementing Ethernet based protocol to transfer data instead of ATM. The comparison of BPON and GPON is shown in Table 1 below. [pic] Verizon uses Multimedia over Coax Alliance (MoCA) technology to provide data communication inside the resident. MoCA is installed in the ONT, Broadband Home Router, and set-top boxes and permits two-way IP data transmission over coax.By using MoCA, Verizon can reduce installation cost by using existing coax cable instead providing Ethernet cables to connect devices in the resi dent. [pic] Fig. 7. Verizon FiOS MoCA Verizon is using two main FTTP deployment schemes, the FTTP Overlay architecture and the FTTP Full Build. The [pic] Fig. 8. FTTP Overlay and Full Build Deployment Choice between two deployment scenarios is dependent on the specific deployment area and the likely take rates. In the FullBuild architecture, the fiber is deployed to each house and each subscriber gets an ONT together.In Overlay architecture, fiber is available to pass all homes and business in a distributed area but only a small percentage of homes and businesses are connected to and served with FTTP [7]. B. AT&T U-Verse In 2006, AT&T launched its U-Verse IPTV service (project lightspeed), comprising a national head-end and regional video-serving offices. AT&T offered over 300 channels in 11 cities through FTTN technology. AT&T utilizes copper pair to connect VRAD to Residential Gateway (RG) using xDSL technology. With U-verse, it can provide 25Mbps to home approximately 2500~4000 f eet away.By using MPEG-4 H. 264 compression technique, U-verse can provide 4 simultaneous TV stream (2HD and 2 SD TV), 2 VoIP and POTS service to the resident. Figure below is U-verse architecture. [pic] Fig. 9. U-verse FTTN Architecture The DSL technology at its beginning stages could only deliver 6 Mbps but now with ADSL2+ and VDSL, it can provide much higher bandwidth over a single copper pair. [pic] Fig. 10. xDSL technology. The various techniques are being implemented to improve the bandwidth and physical loop length capabilities of different DSL technologies.Bonding copper cable pairs can provide higher bandwidth by terminating 2 copper cable pairs together to act as 1 larger copper pair. ADSL2+ and VDSL is bonded together to provide higher bandwidth. VDSL can provide higher throughput than ADSL2+ however, it can only support short loop length. There is newest xDSL technology standard VHDSL2, which approved in February 2006, can provide bandwidth of 200 Mbit/s but maximum dist ance of 300 meters. xDSL technology goal is to provide VDSL speed with longer loop length [4]. The various different xDSL technology characteristics are shown in table below. TABLE 2. xDSL SELECTED CHARACTERISTICS. pic] AT&T typically uses mix of xDSL technologies to deliver broadband service to subscribers. Mainly ADSL2+ from the central office and VDSL2 from the VRAD through FTTN fiber based technology. C) Cable TV to IPTV Transition Cable companies are the largest subscription television service provider in the world and can easily integrate IPTV services to their existing infrastructure. In cable TV infrastructure, there are two main categories of digital video services: broadcast and on-demand Broadcast service defined as a service in which one copy of a program is sent to all subscriber in a broadcast manner.Broadcast services include : – Digital broadcast- Encoded/compressed programs are sent to a subscriber’s STB, where they are decoded/uncompressed for playbac k on a TV. All programs are transmitted regardless of which programs are currently watched by the customer – Switched digital video (SDV) – SDV is similar to digital broadcast but only requested programs are sent to a subscriber group. This group typically consists of all the subscribers served by HFC node which can serve range o 125 to 2000 subscribers. SDV is first two-way communication with subscriber for program selection.The digital broadcast architecture begins with the polling the content in the headend from satellite and terrestrial sources. The acquired content is generally forward to a multifunction media processing device performing following three functions: – Statmux – performs statistical time-devision multiplexing of real-time video content from various sources. – Groomer – adjust rates of content into a maximum bandwidth and limiting the rate of video burst – Splicer – inserts ads into programming breaks as need ed for a regional market. [pic]Fig. 11. CATV Architecture. The content is then forwarded across IP transport network to an IP-enabled quadrature amplitude modulator (QAM), where video content is encrypted and forward to STB for the customer. An out-of-band (OOB) channel provides the STB with basic tuning information, basic tuning information, decryption keys, software upgrade, and other communications. Switched Digital Video (SDV) was designed as a cost-effective method to expand bandwidth capacity in a way different than plant upgrades or better video compression method.Traditional digital broadcast sends all the channels into the HFC network but with SDV, programming terminates at the headend (VHO) or hub (VSO) and does not send channel unless it’s requested. When an SDV program is selected, tuning software in the receiver sends an upstream message and SDV session manager receives the quest and maps the program to a frequency within the allocated pool. If the program is alr eady being viewed within the same subscriber group, the task is as simple as reusing the existing session frequency information. On-Demand service is an interactive service where a requested video program is streamed to one subscriber.All on-demand content is encoded/compressed and stored on server to be received by individual subscriber’s request. On-demand services include following: – Video on demand- Content is stored on a server and subscriber views a list of titles and requests to view a specific title. The VOD system authorizes and streams the requested content to the requested user. – Network-based personal video record (nPVR) – this service is like home PVR except the content is on the service provider network. A subscriber uses the STB to record specific content to record and watches content at a user-chosen time which is same manner as VOD. pic] Fig. 12. Integrated Cable Video Service Architecture Cable IPTV architecture needs three newly added components to enable IPTV to their customers: Cable modem (CM), Cable Modem Termination system (CMTS), and a PacketCable Multimedia (PCMM). [pic] Fig. 13. Cable IPTV Architecture The CMTS and CM provide a two-way IP over DOCSIS transport in the HFC network. Cable Companies are moving toward M-CMTS technology, which can separate, MAC and PHY layer to improve scalability of DOCSIS transport unlike traditional CMTS where both MAC and PHY layer in a single device.In order to utilize IPTV in Cable company network, IP STBs or other IPTV capable devices must be able to receive video over IP transport and remove network delay variation. Major Cable companies are finding hybrid STBs as attractive solution for IPTV. The Hybrid STB with an embedded cable modem can receive video from either IP path or traditional QAM/RF transport path, which is good strategy to migrate from traditional cable architecture to IPTV. Admission control in Cable IPTV can be applied to both the IP network from the vi deo source to the CMTS, and the HFC network between the QAM and the CM through PCMM policy server.Policy server in DOCSIS networks defines QoS policies for CMTS to enforce them. Admission control signaling can be categorized as off-path and on-path. Off-path is when the control path is different from the data path and on-path signaling traverses the data path for bandwidth requests that use the commonly selected Resource Reservation Protocol (RSVP). In order to provide better IPTV services to the customers, Cable industry must improve bandwidth efficiency in the last mile. The biggest recent innovation to optimize available bandwidth is SDV but additional solutions are becoming more important as cable company transition to IPTV service.QAM sharing holds great promise of improving bandwidth efficiency without the need of major change in their current infrastructure. However, there are several factors contribute to the bandwidth efficiency of QAM sharing: †¢ Even if SDV and VOD h ave the same peak hours, a viewer is likely to receive only one service at a time. †¢ The gain of QAM sharing comes from the statistical advantage of a bigger QAM pool, shared by two or more services. †¢ Differing peak hours of DOCSIS and video service contribute additional gains.For instance, the spectrum allocated for DOCSIS commercial services during the day may by reallocated for video services in the evening. Dynamic QAM sharing is being realized through new technologies and standards for the following reasons: †¢ The DOCSIS M-CMTS architecture, which separates the DOCSIS MAC and PHY protocol layers. This allows the PHY layer (specifically the QAMs) to be dynamically allocated and de-allocated. †¢ The recent emergence of universal QAMs, which can function as either MPEG video QAMs or DOCSIS QAMs. †¢ Standardization in edge QAM resource management. pic] Fig. 14. Dynamic QAM Sharing with M-CMTS Architecture ERMI specifies several interfaces to an edge res ource manager (ERM). The ERM is a plat- form that manages and leases QAM channel bandwidth for all applications: †¢ ERMI-1 is an interface for edge devices to register QAM channels to the ERM and notify the ERM of any QAM failures or state changes. †¢ ERMI-2 is an interface for the ERM to bind the QAM resources from an edge device to the resource allocation request. †¢ ERMI-3 is an interface for the M-CMTS core to allocate QAM-channel andwidth from the ERM. Variable bit rate (VBR) video provides considerable bit saving compared to constant bit rate (CBR) video. WITH VBR statistical multiplexing, Cable Company can save as much as 30 percent of bandwidth by just varying the output data per time segment. Recently, DOCSIS 3. 0 was release to compete with Telco companies FTTx deployment and it is redefined the communication between cable modem (CM) located at subscriber premises and cable modem termination system (CMTS) at cable service provider’s network headend. D OCSIS 3. are design to allow channel bonding to boost up network throughput and number of bonded channel is usually 4 or 8. With DOCSIS 3. 0 standard, it can provide 300 Mbps download and 100 Mbps upload [8]. TABLE 3. DOCSIS 3. 0 Standards and Characteristics [pic] D) Netflix OTT IPTV System and Architecture Netflix is the leading provider of OTT on-demand internet video streaming in the US and Canada with more than 23 million subscribers. Netflix can stream out HD quality video with average bitrate of 3. 6 Mbps and it is single largest source of Internet traffic in the US by consuming 29. % of peak download traffic. [pic] Fig. 15. Netflix Architecture Designing large-scale network infrastructure to support fast growing video streaming platform with high availability and scalability is technically challenging. The Majority Netflix infrastructure used to be hosted in its own datacenter but recently resorted to the use of cloud services, Content Distribution Networks (CDNs), and other public computing services. Amazon AWS cloud is being utilized by replacing its in house IT infrastructure along with SimpleDB, S3 and Cassandra for file storage.Video streaming is distributed out of multiple content distributed networks (CDNs), UltraDNS, and a public DNS service is used as its authoritative DNS servers. Microsoft Silverlight is employed as the video playback platform for Netflix desktop users and Netflix manages to build its IPTV with little infrastructure of its own. †¢ Netflix data centers – Netflix uses its own IP address space for the host name www. netflix. com. This server primarily handles registration of new user accounts and captures payment information and redirect users to movies. etflix. com or signup. netflix. com. This server does not interact with the client when handling movie request and playback. †¢ Amazon Cloud service – Most of the Netflix servers are served from various Amazon cloud services and key functions are content ingestion, log recording/analysis, DRM, CDN routing, user sign-in, and mobile device support †¢ Content Distribution Networks (CDNs) – Netflix utilize multiple CDNs to deliver the video content to the subscriber. The encoded and DRM protected videos are stored in Amazon cloud and copied to CDNs.The three main CDNS are Akamai, LimeLight, and Level-3. These three servers provide same quality level content to all the subscribers. †¢ Player – Netflix employ Silver light to download, decode and play Netflix movies on desktop web browser. There are different players for mobile phones and other devices such as Wii, PS3, Xbox, Roku, etc. Netflix utilize Dynamic Streaming over HTTP (DASH) protocol for streaming. In DASH, each video is encoded at several different quality levels and is divided into small chunks. The client requests one video chunk at a time via HTTP.With each download, it measures the received bandwidth and runs a rate determination algorithm to deter mine the quality of the next chunk request. It allows the player to freely switch between different quality levels depending on the bandwidth of subscriber. TABLE 4. KEY NETFLIX HOSTNAME [pic] Netflix Client player have many functions to improve its performance and quality of experience (QOE). Netflix video streaming is controlled by instruction in a manifest file, which Silverlight client downloads. This metafile provides the DASH player metadata to conduct the adaptive video streaming capability.It is client-specific and generated according to each client’s playback and bandwidth capability. It is in XML format and contains several key pieces of information including list of the CDNs, location of trickplay data, video/audio chunk URLs for multiple quality level, and timing parameters such as time-out interval, polling interval and other data to provide QoE to users. Manifest files ranks CDNs to indicate which CDNS are preferred for content delivery. Trickplay is achieved by downloading a set of thumbnail images for periodic snapshot during network congestion [15]. IPTV multicasting protocolIn early IP networks, a packet could be sent either in unicast (single device) or broadcast (all devices). With multicast, single transmission for a group of devices is possible. Multicast transmissions enable efficient communication between groups of devices by allowing Data to be transmitted to a single multicast IP address and received by the group of interest. Multicast over IPTV network presents many challenges related to reservation of resource and maintaining quality of experience (QoE). Backbone can be built based on IP/MPLS and the routers can be enabled for multicast using IGMP protocols.Before going into detail of multicast protocol in IPTV, we will discuss multicast protocol in detail and how it can help IPTV through multicast mechanism. TABLE 5. IGMPV2 AND IGMPV3 MAJOR DIFFERENCE [pic] The IGMP was defined to allow a host computer to select a stream fro m a group of multicast streams a user request. Following is the basic functions IGMP protocol: †¢ Join: an IGMP host indicates that it wants to receive information from a multicast group to become a member. †¢ Leave: An IGMP host indicates that it no longer wishes to receive information from a multicast group. Query: An IGMP router can ask the hosts which groups they are member of. This is done to verify a JOIN/LEAVE request or to look for error conditions. Queries maybe be: o Specific Query: Asks whether the host is a member of a specific multicast group o General Query: Asks the host to indicate all groups that it belongs to †¢ Membership Report: an IGMP host tells the IGMP host what group it belongs to. This report can be either: o Solicit Membership Report: Sent in response to a QUERY o Unsolicited Membership Report: initiated by the client.In the IPTV network, each broadcast TV channel is an IP multicast group. The subscriber changes the channel by leaving one gr oup and joining a different group. IGMPv1 is not suitable for IPTV because it does not include an explicit â€Å"Leave† capability. The client will continue to receive all requested stream until the multicast router issues next query. The standard for IGMPv2 and IGMPv3 major difference is shown in Table 5. IGMPv2 supports Any Source Multicast (ASM) networks and which allows host to specify which multicast group it wishes to join.Most deployed IPTV clients supports IGMPv2. The Major enhancement in IGMPv3 is that it allows Support Specific Multicast (SSM). Host can specify the source address it wants to listen to. Here’s basic IGMP operation involving two devices: †¢ IGMP host (client or STB) – issues messages to join or leave a multicast group. The client also responds to queries from the multicast router. †¢ IGMP router – responds to the join and leave messages to determine if multicast groups should be forward out an interface. Periodic queries are used to discover from error conditions and verify requests.The IGMP router receives multicast groups either through the use of a multicast protocol such as PIM or static flooding. It is the termination point for IGMP messages and does not send any IGMP information to its upstream neighbors. [pic] Fig. 16. DSL Access Network IPTV Service In xDSL IPTV architecture, the subscriber initiates channel change requests and responds to status inquiries. The Routing Gateway (RG) at the subscriber’s site and DSLAM aggregate traffic from multiple subscribers in order to act on request from the STB.However, IGMP networks were not originally designed to have networking equipment between IGMP client and the IGMP routers. This creates some challenges to the multicast implementation: – Excessive multicast traffic: When delivering high bandwidth IPTV over broadband network, it is important to ensure that IPTV channels are forward only to those subscriber currently viewing them sinc e bandwidth is scarce. If the intermediate devices are unaware of IGMP flows then all multicast traffic is broadcast out all ports – Excessive IGMP traffic: Extra bandwidth is consumed as IGMP flows are broadcast to across the network.A single STB IGMP request can result in responses from thousands of IGMP peer clients. – Excessive time to Leave a group: With small spare bandwidth in broadband networks, Leave request often must be processed before additional join request can be served. To mitigate above challenges, several techniques are proposed and developed in intermediary devices: Local Replication, Proxy routing, Proxy Reporting, and Immediate Leave. Local replication, IGMP snooping from DSLAM, allows DSLAM to inspect incoming IGMP Join and Leave request and take appropriate action.If the channel being requested to view is already being received at the DSLAM, it will replicate the stream and forward to the subscriber. The DSLAM builds a table to track which channe l are being forwarded to each port. [pic] Fig. 17. DSLAM with IGMP Snooping Proxy routing works by allowing intermediate device (DSLAM) takes active role of terminating all IGMP flows. This makes DSLAM to act as IGMP host and responds to all incoming requests. DSLAM will recreate the IGMP request and use its own IP address as source.The major benefit of proxy routing is scaling since router is not aware of individual subscribers. [pic] Fig. 18. IGMP Proxy Routing Proxy Reporting reduces the number of IGMP packets flowing across the network by selectively dropping IGMP packets that are not need to be forwarded. The Proxy Reporting can be subdivided to two categories: Query Suppression and Report Suppression. Query Suppression reduces traffic between the DSLAM and the subscriber premises by having the DSLAM intercept and respond to IGMP queries sent by the router.DSLAM will never send a specific query to any clients and forward general queries only to those client receiving at least o ne multicast group. [pic] Fig. 19. Query Suppression. Report Suppression reduces traffic from DSLAM to the router by having DSLAM aggregate the response. The DSLAM can intercept IGMP reports coming from STB and forwards a summarized version to the IGMP router only when it is necessary. There are two categories of reports. Unsolicited membership reports are forward when first subscriber joins a multicast group or last subscriber leaves a multicast group.This tells router to begin or stop sending channel to this DSLAM. Solicited membership reports are forward once per multicast group. The DSLAM will aggregate multiple responses together into a single membership report to save bandwidth. [pic] Fig. 20. Report Suppression Immediate leave alleviate IPTV challenge to change channel rapidly. The standard IGMP Leave operation for channel change is as follow: – The STB sends a request to leave one multicast group – Router responds by issuing Membership Query to confirm the requ est. The STB responds with a Membership Report which does not include the multicast group By implementing immediate leave, STB can leave the multicast group by just simply sending a request to leave one multicast group [16]. [pic] Fig. 21. Standard IGMP Leave and Immediate Leave. The emerging IPTV deployments utilize Real-time Transport Protocol (RTP) in order to deliver media content. Unlike UDP, RTP protocol can provide sequence numbers to maintain packet ordering and detect losses, and timing information to determine network delay and synchronize timing between senders and receivers.RTP control protocol maintains session state between senders and receivers and report sender and receiver statistics bi-directionally [17]. The rapid acquisition is illustrated in the Fig 22 flow diagram below. [pic] Fig. 22. Rapid Acquisition Flow Diagram 1) The RTP receiver sends a Multicast Leave message to its upstream multicast router to leave the current multicast session and end the currently v iewed channel. 2) The RTP receiver sends a feedback message to the feedback target asking for rapid acquisition for the session it wants to join. In this feedback message, the RTP receiver can specify its specific requirements. ) The retransmission server receives the feedback message and decides whether or not to accept the request. If the retransmission server accepts the request, it sends a message to the RTP receiver that describes the burst that the retransmission server will generate and send, including the indication when the RTP receiver should join the new multicast session. The unicast burst stream consists of retransmission of a specific block of packets which will allow the RTP receiver to begin displaying video without waiting for a certain random access point to arrive in the multicast flow.If the retransmission server denies the request, it informs the RTP receiver immediately. 4) If the retransmission server accepts the request, it transmits the unicast burst data an d any additional message(s) needed to carry the key information about the new channel. The key information is used to prime the decoder inside the IPTV STB so that it can start decoding sooner. The unicast burst continues at a higher than natural rate until the unicast burst catches up with the real-time multicast flow. The sustainable burst rate depends on the access network link characteristics. ) At the appropriate moment (as indicated or computed from the burst parameters), the RTP receiver joins the new multicast session by sending a Multicast Join message to its upstream multicast router. 6) The RTP receiver starts receiving the multicast flow and completes the rapid acquisition. The STB will not join multicast session immediately with rapid acquisition since there would not be enough available left over on the access link. By utilizing unicast burst sent from the retransmission server o catch up with the multicast flow in a reasonable amount of time before joining to multicas t group allows faster channel switching capability rather than joining multicast group immediately [18]. Cloud Computing service in IPTV IPTV videos can be delivered to subscribers through various different network structures. For many years, Proxy servers have been utilized to decrease network traffic and delays through high speed and robust connection. Telco companies are looking for ways to keep service calls rejections to minimum through cloud service for on-demand IPTV service. Figure below shows on-demand IPTV service for cloud architecture. pic] Fig. 23. On-demand IPTV cloud services Video can be streamed from any of the virtual servers by load balancing among server and handle peak loads by avoid overload to achieve continuous, high utilization levels of servers. Virtual servers can provide low cost computing resources. The Virtual server acts like a dedicated server but it co-reside on a single physical machines acting as multiple physical dedicated server. However, if too many virtual servers reside on the single physical machine, services may face problem due to scarce computing resource per virtual server.Virtual storage through cloud computing allow easy share of resources among themselves. Physical storage is virtualized into virtual disk, which allows storage consolidation across heterogeneous vendors and protocols, enabled by dynamically growing and shrinking of storage through live migration, in the enterprise storage area network to be used by applications [22]. F uture application of IPTV The key to differentiating IPTV from traditional TV service of VOD and Network-based personal video record (nPVR) is the real-time interactive application and social TV.With FTTx or Gigabit Ethernet providing more bandwidth in broadband network allows new killer application to maximize the value of the IPTV service. A) SayUTV SayUTV service allows users’ participation into TV sports, discussion, variety show, and so on. SayUTV allow mixing their vide o and sources into provider’s content to allow maximum interactive and customize IPTV content. The subscriber can click participation button on SayUTV GUI. After service provider or host of the content allows his/her participation, the subscriber’s audio and video content is mixed into program’s content.All the viewer of the content can view the participant’s image and voice. [pic] Fig. 26. SayUTV Service System Architecture SayUTV service divides the role of users into three major roles: †¢ Controller – who creates a service session and has a control over that session. †¢ Participants – who joins the session and contributes his/her own multimedia content. †¢ Simple Viewer – who enjoys this service in a passive way [pic] Fig. 27. SayUTV Implementation. SayUTV is an advanced IPTV service, which combined with bidirectional multimedia communication technologies allowing interactive user-participation [20].B) IPTV Interacti ve Online Shopping In order for IPTV service provider to maximize the profit from IPTV service require smart ad insertion based on customers’ preference. TV series and sports media are well known for effective product advertisement aid. Apparels worn by a main actress of TV series or MVP sports athletes have greater potential for larger sales than conventional display by online shopping website. In order to provide customer’s shopping craving while watching TV series or sports event is to add additional information to the product description field such as TV series name, and character or athletes name.This will allow customers place some tags on that particular product through watching particular TV series or service provider can collect customers’ preference based on content and insert smart ad targeting each subscriber. [pic] Fig. 28. Shopperama Service Screen in Korea Shopperama is OTT provider in Korea providing series, which have broadcasted through a TV st ation, online along with smart ad insertion. The apparels worn by main actors and products inside the episode are displayed in a synchronized manner with video content as shown in Fig 25.This allows customer to shop for products very easily while watching TV series and reduce customer’s burden of trying to find particular product [21]. To improve interactive online shopping with IPTV service still needs many enhancements to fully flourish in E-business model. Behavior targeting content to users is estimate to be 20 billion dollar industry and in order for IPTV interactive online shopping to gain market share requires smart integration of cross layer platforms. C) Final Remarks With IPTV service deployment, Cable Company is afraid of cord-cutting case.The IPTV service is gaining popularity amongst consumer and there are many opportunities for new killer application to integrate with IPTV service. In this paper, we described current IPTV architecture in the market and presented recent efforts to improve IPTV technology. 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K. ; Seung Hun Oh; Sim Kwon Yoon; Ho Young Song; , â€Å"An implementation of user-participated interactive IPTV service system,† Consumer Electronics, 2008. ISCE 2008. IEEE International Symposium on , vol. no. , pp. 1-3, 14-16 April 2008 21] Jonghoon Chun; , â€Å"In teracitve Online Shopping Innovation,† Computers, Networks, Systems and Industrial Engineering (CNSI), 2011 First ACIS/JNU International Conference on , vol. , no. , pp. 104, 23-25 May 2011 22] Phooi Yee Lau; Sungkwon Park; Joonhee Yoon; Joohan Lee; , â€Å"Pay-as-you-use on-demand cloud service: An IPTV case,† Electronics and Information Engineering (ICEIE), 2010 International Conference On , vol. 1, no. , pp. V1-272-V1-276, 1-3 Aug. 2010

Friday, January 10, 2020

Language and the Text of Each Paper Essay

In this essay on the Brixton riots I hope to show how different newspapers can express the same basic facts in different ways to make the reader feel a certain way about the event – in this case, the Brixton riots. I will be looking at the front pages of two newspapers (which I call papers 1 and 2 in the essay), each of which describe the same event and include similar facts. The Brixton riots occurred in 1981 in Brixton, London, and were between the residents of Brixton (predominantly black) and the police forces. They came about in the first place because of historical background reasons and social reasons. Blacks had a history of low-ranked jobs with low pay. Since the British Empire broke up and the citizens of the Commonwealth countries, mostly black, moved to Britain, a lot of them were prepared to take low-ranked jobs so they could stay in the country. This meant that people in Britain associated them with being low-class. There were very few black people with high-ranked jobs. With people associating black people like this, it led to racism and general abuse. With all this abuse the blacks started to build up a stereotyped view of white people and because few black people had good jobs a stereotyped view of the police was built up as well. This meant that the tension was raised because each side mistrusted the other. The event that started off the Brixton riots occurred in Coldharbour lane in 1981. A policeman was on duty when a young black boy ran past him. The policeman, suspicious of the boy, ran after him. As he did so he tripped over the boy, badly injuring him. This aggravated the black community. Before this incident, the police had been given power to stop and search anyone they felt was suspicious which meant that the atmosphere in Brixton was tense. On the social side, in 1981 the Conservative government was in power with Margaret Thatcher as their leader. The less well off were dissatisfied with what the Government were doing. They hadn’t really done much at all to help young blacks. It was likely that if you were young and black at this period you would be unemployed. This meant that there was a lot of tension around, which helped to spark off the riots. With the riots being a shocking event, the press immediately got involved. This led to the events being sensationalised and being used as a money making scheme. When there is big news that is in the newspapers for quite a while, the papers develop a logo. Logos are used to structure and organise the paper . The readers get used to seeing a certain logo and they associate the logo with an event. Here it would be the Brixton riots. This helps the readers to find their way around the paper more easily. These logos seem to be giving a number of different impressions of the riots. In the captions beneath the logos a lot of the words seem to be in the semantic field of war. Words such as ‘battle’ and ‘war’, which are good examples of this semantic field, give the impression that the riots were very violent. The logo pictures are mostly of the same policeman with blood running down the side of his face. These images give the impression that there were some bad injuries in the riots and that the riots were very violent. However the fact that the logos are mostly concerned with the same image suggests that the injury inflicted on this policeman was perhaps the most dramatic injury there was in the riots. Even so, head wounds often appear to be much worse than they really are, which suggests that the riots were not so serious as the papers make them out to be and were, in fact, blown out of proportion. This image has been selected to attract the reader’s attention. If this were on T. V. it would still be easily possible to select and bias like you can in newspapers. A lot of news programmes choose their stories very carefully to ensure that a certain viewpoint is supported. Another way to manipulate facts is to take a very biased viewpoint . Two possible viewpoints are political and non-political. Newspaper 1 does seems to have a political viewpoint as it is taking pity on the police and is making them seem like the victims by criticising the rioters. This indicates that this paper takes the side of establishment and law rather than that of the rioters, the neglected residents of Brixton. Headlines such as ‘Police under Attack Again in New Fury’ makes the police out to be the victims and the mob to be a reckless, aggressive one. Headlines that demonstrate a particular viewpoint will attract the readers’ attention as they make the subject more dramatic. Newspaper 2 has a very different viewpoint, seeming to imply that the police were causing almost as much trouble as the rioters. ‘Eight police coaches, each containing forty men, were rushed to the area, further raising the tension’ suggests that this paper is taking the side of the rioters. It very much puts the blame on both the police and the Government and sympathises with the people of Brixton in its headlines . It is used here mainly to prejudice you even though it is opinion. ‘Police harassment’ and ‘Arrest sets off more clashes’ suggest that the main reason that the riots started was because of unnecessary action taken by the police. Other headlines, such as ‘No hope of jobs’ and ‘Decaying housing’, are blaming the Government for agitating the people of Brixton by not providing enough employment or repairing their houses. This could also be biased on T. V. as the editor could put forward only half of the full story ,so biasing the As well as having a very biased viewpoint to attract the readers, the paper can be made more attractive and eye catching. The front page of newspaper 1 is very eye-catching indeed. As soon as you look at it, your attention is drawn to the photograph and ‘BATTLEFRONT’ in large letters, the battlefront being the front line of the rioting. This banner headline, white lettering on a black background, takes up the whole width of the front page and is designed to make it stand out and catch your eye. The picture dominates the page and all the writing is positioned around it, making it the focus of the article. Also the headline, ‘The picture that sums up the horror of Bloody Brixton’, makes you look expectantly at the picture as well as using alliteration to draw your attention to it. The use of a capital letter for ‘Bloody’ gives the riots a historical connotation, as though it is already a well known event. Newspaper 2 has a much simpler front page, with a simple black headline, a subheading and a picture. Unlike on newspaper 1 the headline does not draw your attention to the picture, because it is not specifically related to it. Although there are some banner headlines across the top in bullet point form, displaying points such as ‘No hope of jobs’, they are much smaller. I think that this paper is less sensational and a bit more ‘refined’ than the other, typical tabloid newspaper. The headlines used in newspapers and the wording in them is another way to catch the readers attention . The headlines in a newspaper are very important as they often tell the reader what point of view the paper is taking, the nature of the event – if referring to one – who is involved, where it happened, and other bits of information as well. It is very important for a tabloid newspaper to use exciting and exaggerating vocabulary in them as this really helps to catch the readers’ attention and make them think that something very dramatic has happened. In newspaper 1, this has been done by using words such as ‘battlefront’. A word like this is obviously in the semantic field of war, making the events seem more dramatic. Other headlines, such as ‘Police under attack again in new fury’, make it sound as though the police were being physically attacked by the youths, who are described as ‘furious’. This sentence is in the passive tense whereas the other paper is written in the active. These headlines seem to be in a similar field of meaning and connotation as they are both associated with violence and the police being under attack. In newspaper 2, however, the headlines suggest different things. Headlines such as ‘Brixton points the finger’ and ‘Arrest sets off more clashes’ seem more thoughtful, as if the newspaper has analysed the events, not just exaggerated the happenings in them. They make it seem like Brixton is pointing the finger at the people who are doing the arresting (the police).

Thursday, January 2, 2020

Sample Resume Batteries Not Required...

RE: Batteries Not Required -HotTexasCowboyxCandy_demon21- In all of her life, Knight had never witnessed someone move with so much grace; even the Prima ballerina of the Russian Ballet didn’t move like Colin did, even that alone had made the young woman squirm visibly beneath her robe. The moment he touched her, when his hands held both sides of her face, she could swear that she had felt a shock of electricity shoot through her and awaken every single cell. The gentle massaging of his finger at her temples with drew a long, shuddering sigh. As he spoke, she nodded her head slowly, trying to will her wild heart to slow to match his own: it didn’t work quite as well as she had wanted. The tickling brush of his breath against her skin†¦show more content†¦But as his body left her’s, his form inched down her own, all thoughts evaporated. The fiery trail of kisses hadn’t ended at her neck, instead her sex god had opted to slide down over collar bone to one shoulder then back across the the other direction; he was through, that much was certain . Her body screamed violently for him, to have him take the pinched tip of her nipple into the confines of his warm, wet mouth. She wanted it, no, needed it at this point. Yet even as her form screamed loudly for him to tease her sensitve nubs, he stayed his lips and opted to have his trail of feverish kisses trace down the plains between her breasts. She had never known that watching someone taste her skin, their tongue teasingly caress the inner swell of her breasts, could be so erotic. She hadn’t noticed that as she watched him, she was holding her breath, until he returned to his previous pass and a sound that resembled a whine escaped. Perhaps it had been the agonized sigh that had caused her lover to take action, or it had been of his own volition, but Knight watched Colin lower his mouth hover just over the tip of her breast. Her heart was already hammering against her ribs, but as he teased her with the prospect of taste her pointed nipple, it thundered harder. The moment his tongue slide from his mouth and he began to trace just out of reach, Knight could feel her legs beginning to quake with desire. With each expert circle, he moved closer to her desire goal, it

Tuesday, December 24, 2019

Douglas C 47 Gooney Bird - 979 Words

Research Paper: Douglas C-47 â€Å"Gooney Bird† The C-47 was the lead plane of the 37th troop carrier squadron, dropping elements of the 82nd airborne division near St. Mere Eglise, France in the early hours of June 6th, 1944. June 6th is formally known as D Day. The C-47 was very important to aviation or even the most important because over 13,000 planes were sold, it was one of the most successful cargo planes, every branch of the U.S military and all the major allied powers flew it during World War two. The Douglas C-47 was manufactured in December 7th, 1935. It was manufactured by Douglas. The C-47 was the military model of the DC-3. It could travel 1,600 miles, it could carry up to 6,000 pounds of cargo, and it could also carry 28 soldiers in full combat fear. As a medical airlift plane, it could accommodate 14 stretcher patients and three nurses. Seven basic versions were built. Every branch of the military flew it and all the allied powers flew it. The Navy version of the C-47 was the R4D. The aircraft operated in every continent in the world and participating in every major battle. The outside of the Douglas C-47 was a fundamental shape of smooth rolling contours, low mono-plane wing set, tubular cabin and a single vertical tail. Two engines where mounted on each wing providing 1,200 horsepower. The co-pilot and the pilot sat at the extreme front of the fuselage with the observation blister directly behind the cockpit. The doors were situated at the forward and aft

Monday, December 16, 2019

Purchasing Best Research Paper Writing Services Reviews

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