Research Paper on Satellite Communications

Research Paper on Satellite Communications 1. Overview The role of satellite networks in global communications is growing at an unprecedented pace. From direct broadcast satellite (DBS) television, to satellite phones, to credit card transactions, to the Internet, corporations and consumers are embracing these new services and placing demands on bandwidth. With this demand have come expectations in terms of basic service costs, hardware costs, and ease-of-use. These expectations have forced the industry to examine its traditional ways of operating in order to make satellite services as accessible and convenient as its terrestrial competitors. Recent current events, such as the World Trade Center tragedy and its aftermath, have demonstrated our need for and how reliant we have become on communication medium. As the World Trade Center lay in ruins, also destroyed were a vast array of communication equipment from transmission antennae for radio and TV stations to switching equipment for phone service. Though throughout all this people were still able to communicate, TV and radio stations were still transmitting their signal. Much of this was a result of wireless and satellite technology. With this paper I plan to explain the ever-growing world of satellite communication. How it is changing the way we perform our daily tasks and how it has effected our lives in general. How different businesses have adapted to and the ways they have begun to utilize these new technologies. Furthermore, we will take a look at what new theories and technologies are on the horizon. How these could effect our lives. When and who is trying to implement them, and to what cost, monetarily and professionally. 2. Satellite Communication at a Glance From the late 1950s with the launches of Sputnik and Explorer I, satellites have become a growing part of our world. From various types of platforms many different applications are run through these satellites. Since the first commercial model launched into orbit in 1965, the communications satellite has become the linchpin of global communications. From modest beginnings the first satellite could only handle 240 voice transmissions at a time the technology has blossomed to the extent that satellites now carry about one third of the voice traffic between countries and essentially all the television signals between countries. The backbone of this system is the geosynchronous orbit satellite (GEO), these are large communication satellites placed in orbit roughly 36,000 kilometers above the same spot on the earth at all times. Because of this high orbit each satellite is able to see about one quarter of the earth, so only four or so are needed for global coverage. Drawbacks to these satellites are that due to the high altitude it takes a quarter of a second for signals to travel to and from the satellite, delaying the responses during a conversation. Also the higher altitude means a weaker signal so larger antennas are needed to maintain overall coverage. The next layers of satellites are middle earth orbit (MEO) and low earth orbit (LEO). MEO satellites are generally placed in orbits above 10,000 kilometers, while LEO satellites are generally below 1,500 kilometers. Of course now with the lower altitude the signals are stronger so antenna size can be reduced, but with this also comes less coverage so more satellites are required. In the case of the LEO satellites at least 50 are usually required for full global coverage. The reasoning behind the orbit spacing comes from the presence of the Van Allen Radiation Belt. Originally discovered by Explorer I, the Van Allen Belt is composed of energetic ionized particles, which could damage solar cells and perhaps other solid state components. The belt spans altitudes roughly between 1,500 and 10,000 kilometers, thus the spacing. VSAT, very small aperture terminal typically refers to a class of Earth stations with a small diameter in the range of 0.95 meters to 2.4 meters. The terminals have both transmit and receive capability. The majority of traditional VSAT users such as gas stations, convenience stores and banks selected the technology primarily to manage transaction-based applications point-of-sales credit authorization and inventory control. 3. Impact on Personal Life You can see the impact of satellite and wireless communications in everyday life as you take a walk down the street. People everywhere using cell phones, pagers, PDAs. We are becoming a society that is instantly accessible. Though even now the mobile phone penetration into the U.S. make stands at only 35% nationwide, compared to European penetration levels of 65%. Thus we are still only scratching the surface for the potential growth in this field. Another application changing our lives is the Internet. This is a technology basically still in its infancy. The Internet has brought many resources to within the fingertips of the population, such as research, publishing, government services, education, entertainment, shopping, and financial services including investments and banking. Though the largest of these resources now made available is e-mail. E-mail was the introductory item that helped users become more familiar with this new medium. As of 2000 e-mail has become a regular or routine part of everyday activity for 80% of all U.S. households. Though as more people start using these technologies and the types of data and files they transmit change, including graphic material and streaming video, the more strain is being put on the carrying capacity. With this information providers of these services now face the dilemma of how to increase their capacity. The answer seems to be through satellite, as in 1998 alone commercial satellite operations included 1,700 payload launches. Though satellites have had a tremendous effect on how we communicate with one another, one other aspect that they bring to the table is a quality of life issue. Many health and emergency response teams, including the American Red Cross have adopted satellite technology within their means of communication in times of trouble, especially in remote areas. In 1995, Hurricane Marilyn devastated communications in the Virgin Islands and Puerto Rico. The only reliable means of communication at the disposal of the American Red Cross was INMARSAT satellite technology. Satellite phones were used for voice and fax transmissions, as well as data transmissions and packet switching, primarily for disaster welfare inquiries and contacting people to let them know their relatives were okay. This was also the fact when Hurricane Floyd struck the United States. The Red Cross had to patch together a wide range of technologies, from plain phones to two-way radios to satellite phones. They also had to utilize different frequencies to get the necessary coverage required. As stated by Bob Bavis, director of administration for the American Red Cross, The damage was so widespread that nothing covered the whole region except satellite phones. The mixing of different technologies is nothing new to disaster relief efforts. Due to geographic location, and degree of devastation emergency workers have always had to patch together the best qualities of different technologies to provide coverage to troubled areas. The nature of satellite technology its mobility, ubiquity, and flexibility easily lends itself to humanitarian efforts. The help satellite technology provides in disaster relief isnt only limited to the hardware. Companies like Verizon Wireless, has formed a team called the significant event response team (SERT) to respond to emergency and relief agencies in the communities they serve. The team provides wireless phones to public safety agencies and local police and fire departments to help them coordinate emergency operations. Other ways companies are helping is with free airtime on satellite phones and allocation of satellite bandwidth capacity. 4. Impact on Industry Most industry in America has begun integrating wireless, and satellite technologies into their daily routines. This can be seen in everyday life as FedEx employees use wireless handheld devices to help track packages, and determine sender and receiver information to help organizations conduct business more efficiently. To Hertz car rental employees pulling up driver and car rental information in a parking lot, several hundred feet away from their stationary computers. One of the most notable impacts of satellite technology has been in the news media. Although the video images had been jittery, and the audio sometimes dropped off, CNNs use of a videophone in Afghanistan after the events of September 11th proved that content is the most important element in news. Though initially used as a backup to CNNs more traditional satellite trucks, the videophone stepped to the forefront as getting live pictures out of Afghanistan became more problematic. The Talking Head videophone is about the size of a laptop computer, though twice as deep, and costs roughly $20,000. It can be used with any telephone line, ISDN connection, or satellite phone. For reporting out of Afghanistan, CNN used the worldwide INMARSAT satellite service, which requires a dedicated phone and dish, also about the size of a briefcase. Englands 7E Communications Ltd., the manufacturer of the Talking Head videophone, originally developed a unit that could only transmit at 64 Kbps. This forced CNN to squeeze the picture down to a small insert. The rest of the field was then filled with additional information related to the story. 7E has since developed a way to add a second satellite phone to the compression package, which allows transmission at ISDN rates of 128 Kbps, effectively doubling the quality and allowing for full-frame images to be broadcast. CNN first began using the videophones in December 1999, when correspondent Nic Robertson used an earlier model to broadcast exclusive pictures and sound of a hijacking in Kandahar, Afghanistan. The videophone was also prominent when CNN broadcast the first live pictures of the 24-crew members released from the U.S. Navy spy plane in China when they landed on the Pacific Island of Guam. CNNs chief news executive Eason Jordan states the units are easy to use and due to its portability, allows the reporter in the field to broadcast live TV in a matter of seconds. Other fields of industry, not so prominent, have also benefited from advancements in satellite technology. With more than 80 land and offshore drilling rigs around the world, Helmerich Payne (HP), an energy-oriented company engaging in contract drilling, oil and gas exploration, and production worldwide, needed a way to link all of its facilities across a single, central network. The company leveraged solutions from several companies to build and deploy a high speed, satellite and terrestrial-based network that delivers real-time voice and data capabilities to all HP locations. Prior to establishing the satellite network, HP had utilized a dial-up network, coupled with cellular phones for voice communications. The cellular service along was costing the company more than $3,000 a month per rig. Motorola Multiservice Networks Division (MND), integration consulting group FDDI-AVD, and InterSat Communications worked with HP to design and implement a customized solution to expand its existing network, and deliver a high-speed satellite system to connect the companys rigs and offices. A network-in-a-box was developed by combining routers, satellite and servers into a single self-contained unit. The solution was designed around Motorola Vanguard multiservice network units, which enable the convergence of data, voice, and video, while laying the foundation for wireless/wireline integration. The Vanguard units provide HP with on-demand bandwidth to support a broad range of high-speed transmissions, featuring 247 reliability. A microwave and/or satellite network deployed on each rig and remote location connects the companys offshore drilling operations in the Gulf of Mexico with the Tulsa, Oklahoma home office. The network units also offer built-in data encryption and compression features, enabling the secure transmission of sensitive data around the world. By achieving fully integrated field connectivity, HP has improved the companys business operations, offering a host of added benefits, including seamless information exchange, synchronized reporting and reduced telecom costs. Customers on-site can also share the available bandwidth to securely connect with their own internal information systems. Real-time drilling data can also be delivered to the customers regional or headquarter offices, providing them with updated information on each days activities. Some banks are finding that using satellites for data transmission can improve network performance and cut costs as well as provide benefits in staff training and customer satisfaction. Most banks have relied on 56 Kbps landline frame relay services to carry data traffic to and from their branches. But a pronounced increase in traffic, fueled by the explosive growth in Internet-based applications, is increasing clogging these circuits and causing bottlenecks. When reviewing the systems employed by banks in Canada, it was determined that most banks transmit large volumes of data from head office to their branches while branches typically return considerably less data to head office. Telesat, the owner and operator of Canadas fleet of communication satellites, capitalized on this fact to employ a service that uses a high-speed satellite link to transmit data to the branches, and the existing 56 Kbps network then transmits data back to the head office. This service can deliver data speeds of up to 24 megabytes per second more than 400 times faster than a 56 Kbps system. The introduction of satellite technology has also given the banks the bandwidth to offer a comprehensive suite of services to their remote branches that typically lack high-speed landline services. For Canada Trust bank, the service has been utilized to train employees at branches across Canada. Sessions are held at a Toronto studio and broadcast live to 200-300 employees at a time. School systems have also had to beef up their networks to the point where they rival or exceed the capacity of many corporate networks, due to the explosive growth in student Internet usage. School systems around the country have deployed unlicensed wireless networks, tapped the bandwidth of cable television systems and even employed satellite service as a cheaper and more reliable alternative to local telephone companies. The utilization of satellites has also offered the possibility of connectivity to schools in remote areas where they do not always have access to multiple wire-line providers. The University of Alaska, in combination with Starband Communications Inc. has deployed a VSAT satellite service to link 25 communities throughout the state. This deployment was initially designed to test speed and latency, as well as the toll the harsh Alaskan climate takes on performance. 5. Future Developments The telecommunications industry is going to see more technological change in the next five years than it has seen in the past 95 years. Five vital technologies that will contribute to these monumental changes are: Optical transmission Satellite communication Wireless and mobile communication devices Broadband digital technologies Internet resources Each one of these enhanced communication capabilities creates enormous moneymaking opportunities, as well as improvements in cost, speed, quality, and convenience for consumers. Satellite receivers initially were prohibitively expensive, beyond most consumers reach, and the antennas required for receiving signals were so large and unsightly that local governments and homeowner associations barred them from residential property use. Now, dishes measuring about three feet in diameter can be purchased for mere hundreds of dollars. As satellite services continue to improve there will be more encouragement for widespread use of wireless communication. Future advancements in global satellite cellular phone systems seem to be targeting one potential customer the business traveler. Within the business traveler there are two potential markets. First, for those from the developed world who do business in less developed countries where the local phone service may be unreliable, and second, those who need mobile communications in their own countries but travel beyond the reach of terrestrial cellular systems. Several different systems were proposed to handle this project. Two major U.S. based projects are Iridium, a joint venture between Motorola, Lockheed Martin, and Raytheon, and Globalstar, a joint venture between Loral Space and Communications, and Qualcomm. The Iridium plan calls for 66 satellites to be launched in six equally spaced orbital planes at an altitude of 780 kilometers. Services to be provided include voice, data at 2.4 kilobits per second and paging. The Iridium voice connection is more robust than other proposed systems, due to the fact that Motorola requires that the handheld unit be usable from inside a vehicle. The complexity of the Iridium system arises from the fact that the satellites are designed to communicate not only with the earth stations but also with each other. This cross-linking of satellites allows the system to use fewer ground stations, thus preventing signal blockage from buildings, trees, and other obstructions. To assure that traffic is routed properly, each satellite carries a set of routing tables from which new routing instructions are chosen every few minutes. The Globalstar venture, like Iridium, will be based on low earth orbit satellites. Though Globalstar will not employ cross-links between satellites. This means that for a subscriber to gain access a satellite in view would also have to be in view of a ground station. So to achieve global coverage approximately 200 earth stations would have to be constructed. For this reason Globalstar is being targeted more towards business travelers in a single country. The Globalstar system will employ 48 satellites organized in eight planes of six satellites each. The satellite orbits will be circular, at 1,414 kilometers and an inclination of 52 degrees with respect to the equator. The use of an inclined orbit concentrates the available satellite capacity at lower latitudes, where the largest populations exist; little or no coverage is provided beyond 70 degrees latitude in either hemisphere. Deregulation of the telecommunications industry in various developed countries is speeding the delivery of new services and prompting the investment of enormous amounts of capital in new facilities. A key factor in this is the explosion of the Internet. To serve this new market, many new satellite systems are planned, but due to the congestion of the frequencies currently being used for fixed satellite systems, these systems will operate in a higher range of frequencies, known as Ku-band. Though much work is still to be done in this area, as one major drawback to Ku-band, whose wavelength encompasses between one and 1.5 centimeters, is the signal is significantly attenuated by rain. For this reason, the use of Ku-band was confined until recently to use in just a small number of experimental satellites. Now U.S. communications regulators are considering an orbital scheme for broadband Internet users via Ku-band satellites that avoids interference with geostationary communications satellites in the same frequency bands by moving the spacecraft into elliptical orbits, phased to give them the longest hang time over the biggest markets. This approach should effectively double the capacity of near-Earth space to handle broadband satellite communications. One company behind this approach is Virtual Geosatellite, under their plan 15 satellites would occupy separate elliptical orbits measuring about 320 miles high at perigee and almost 17,000 miles high at agopee. With each orbit taking about 8 hours. Virtual GEO calculates it could get about 5 hours of operating time per orbit as the satellites approach and leave apogee. The Virtual GEO constellation would also be offset from GEO satellites by at least 40 degrees, relative to the equator. At that angle of separation, the satellites would not interfere with GEO spacecraft in the same frequency. 6. Advancement, but at What Cost While many companies are looking to the future to see what advancements they can develop to their niche in the communications market. The hard reality is that there is only so much money available to fund the research and develop the needed hardware. This combined with the fact that, in most cases, several companies or alliances are competing for the same piece of the market will cause some to be left behind, no matter whose technology scheme might be better. One case in point is the Iridium project, the joint venture between Motorola, Lockheed Martin, and Raytheon, who declared bankruptcy in 1999. The project, with a projected cost of $3.4 billion, failed to catch on with consumers. Major reasons being people unwilling to spend approximately $3,000 per unit and up to $7 per minute of airtime. These costs were astronomical to the consumer in an era when ordinary cellular telephone networks rapidly expanding. At the time of the bankruptcy filing, Iridium and its affiliates collectively owed creditors more than $1 billion. If itÐ ±Ã ¶s a risky venture, then why are so many companies spending tremendous amounts of money to try to stay ahead of the field. One simple reason, the potential profit is enormous. Annual revenues from telephone services, high-speed Internet access, and imaging generated by satellites are expected to reach $150 billion by 2008, according to the International Space Business Council. Conclusion As we have seen, satellites have had a major impact on our lives, in both personal areas and in industry. The technology has proven its versatility versus other communication formats with its ability to provide service to areas on the globe that are virtual inaccessible to most others technologies. This function has proven to be instrumental in assisting communities in times of strife and has also helped companies establish better information links with their facilities in more remote areas. As the communications market continues to grow at an astronomical rate, the main focus of the industry will be on how improvements can be made in cost, speed, quality, and convenience for consumers. While satellites have been a leading force in providing solutions in these areas, such as the reduction in size of receiver antennas to three feet or less making installation and usage much easier on the customer. The element that will be key to the future is the ability to give access to remote areas around the globe. While in the United States has many systems, especially fiber optic networks, global telecommunication, in many areas, lacks the internal infrastructure to support even the most basic of telephony services. Satellites are an excellent method to establish access to areas with poor terrestrial infrastructures where capacity is either not available or is cost prohibitive. The Internet is another area where satellites can be utilized to provide increased and enhanced service. While now the majority of Internet content resides in the United States, in the very near future increased amounts of content will originate from Asia, Eastern Europe, and South America. Also, the inherent broadcast architecture of satellites makes connectivity highly attractive to Internet service providers (ISP) who are experiencing bottlenecks and network management difficulties due to the exponential demand for bandwidth. As content providers look to push more audio, video, and animation over the Web, satellites may enjoy a unique advantage in the area of webcasting. While satellites enjoy increased accessibility to areas around the world, fiber optics enjoy a much greater capacity and speed potential. Where available future systems should look to mesh these two technologies together. Though meshing these two technologies together would require the development of gateways capable of optimizing the inherent benefits of each, while addressing the differences between the two. The major issue to be addressed will be accommodating the delay or latency due to the slower speeds by satellite, this will cause packets arriving at the fiber network to be dropped.