Satellite Systems and Internet Access - Literature review Example

Satellite Systems and Internet Access Affiliation) Introduction A satellite is an artificial object positioned in the orbit in order to improve communication across different parts of the globe. Satellites are currently used for various uses in areas such as navigation, research, communication, weather and military observation (Houssein, 2013). The satellites may be classified as geostationary orbit, low Earth orbit, or polar orbit depending on how it is used. The satellites are thrust to the orbits by use of rockets. The first suggestion for creating an artificial satellite was made by Newton’s cannonball in his “treatise systems of the world” in 1945 (Salkintzis, 2004). The theory was further developed by Edward Everett Hale in 1869 and later advanced by Jules Verne in 1879. Konstantin Tsiolkovsky wrote about “Exploring the Space using Jet Propulsion devices” in 1903, and in 1928 “The Problem of Space Travel - the Rocket Motor” was published by Slovenian Herman (Maral & Bousquet, 2011). The white house announced the possibility of launching a satellite following the release of the report by project Rand in 1946. Americans considered the use of satellites as a tool for advancing propaganda."Sputnik 1” was the first successful satellite launched by Soviet Union in 1957. These triggered Americans to engage in the cold war as they desired to explore the space (Kota, Pahlavan & Leppanen, 2004). In November 1957, the second satellite known as Sputnik 2 was launched to the orbit. United States managed to launch the first satellite known as Explorer 1 in 1958 after making several unsuccessful attempts. Although currently there several sources of internet, the satellite internet is likely to become more competitive, cost efficient and reliable for users convenience in the future. Main components of satellite system Satellite system is comprised of two distinguished components of apparatus, and they include satellite itself, and ground-based components. These components send signals from the internet users and relay that signal to the satellite that directs the signal to the main server computer after which the data is transferred back to the user via the satellite (Houssein, 2013). Therefore, satellite is always in constant communication with the ground-based components in order to complete the request by the user. 1. Ground-Based Electronic Equipment According to Maral and Bousquet (2011), the ground-based electronic equipments include VSAT dish, which is a two-way satellite ground station containing dish of a specified size and provides aerial that sends or receives the satellite signal. Another part is the indoor modem which facilitates the movement of data via communications satellite. The third part is called teleports which is a station on the ground and is responsible for regulating data exchange across the space links. Also, teleports forms the hub of VSAT Systems satellite internet structure. It hosts the transmitters, control systems, antennae auxiliary power, redundant connections to the internet and HVAC (Salkintzis, 2004). The final electronic component is the Network Operations Center (NOC) which regulates all communication via the satellite connection. 2. The Satellite Equipment The satellite is a geostationary or geosynchronous orbit located 22,236 miles way from the ground and it rotates at the same speed with the earth. For this reason, satellite appears to be immobile by the observer on the earth, and there is no need for monitoring satellites with the satellite dish. This is helpful because it reduces the cost of using satellites in communication and as a source of internet services (Salkintzis, 2004). Another part of the satellite is called transponder space segment and is responsive for channeling information by receiving and resending the data. The current satellites have either 36 or 72 transponders of varying frequencies. The other part is internet backbone which is an enormous assortment of interlinked, high-capacity data paths and central routers for relaying data. The internet backbone links different countries and continents and are useful for businesses and large organizations. How the process works Satellites apply three gears which includes; (a) ground stations or gateways that use radio microwave transmit internet data to and from the satellite (b) geostationary orbit satellite (also known as the geosynchronous Earth Orbit, or GEO), and (c) a very-small-aperture terminal (VSAT) dish antenna with a transceiver positioned at the premises of the subscriber (Maral & Bousquet, 2011). The other internet components include centralized network operations center (NOC) used for controlling the entire configuration and modem at the user end. As for the broadband gateway, the satellite applies star network topology that allows the network transmission to pass through the system’s hub processor at the hub of the star. This offers an opportunity for connecting an unlimited number of VSATs to the satellite network hub (Salkintzis, 2004). The end user computer is linked to the system and to the internet via VSAT systems. When the client opens a particular website in their computer, the end user computer relays the request and both computers relays and receives the requested data. When an application is launched from the end user PC via a private network to the internal satellite modem it modulates the signal and connects it to the satellite stationed at the geostationary orbit at a speed of light (Houssein, 2013). When the geostationary orbit receives the signal, it transmits it to one of the VSAT Systems teleports stationed at Akron in Ohio. The cutback of inter and intra domain routers minimizes latency, thus enabling the packets of data to bump fewer network even though those data packets cover terrific distance. The NOC of the VSAT receives the application and then retrieves the requested website from the web server across internet backbone in the United States (Salkintzis, 2004). The entire process is reversed thus allowing the data to be accessible to the client. Customer Location Teleport Satellite Modem & Router Satellite Hub NOC Internet Backbone Client’s Work Station Source: Houssein (2013) Satellite internet connection A satellite internet connection is as an arrangement that enables the outgoing data to be sent or received by computers via a satellite (Kota, et.al, 2004). The subscriber’s hardware components include a satellite dish transmitter and a transceiver that functions in the microwave section of the radio continuum. In one-way satellite internet connection, the request of data by the client is sent via a telephone line while the feedback of the requested data is sent via satellite. In the two-way satellite, internet consists of approximately a two-by-three foot dish, two modems (one for uplink and the other one for downlink), and coaxial cables between the dish and modem (Salkintzis, 2004). The two-way satellite internet connection allows the uploaded data to move at a relatively lower speed than the downloaded data forming asymmetric linkage. The speed of uploading information in a single computer user ranges from 50 to 150 kilobytes per second (Kbps) while the downloading speed for the same computer is between 150 to 1200 Kbps (Maral & Bousquet, 2011). The efficiency is influenced by the internet traffic, server’s ability and the magnitude of files being downloaded. The military satellites are used for the monitoring objects in the earth’s orbit. They keep track of several artificial objects sent to the orbit for security reasons. However, there are other satellites performing other missions other than monitoring. For example, fixed satellites are responsible for voice, data and video transmission across different countries or continents between certain points on the ground plane. Initially, communications satellites were developed to offer voice telephone service across the globe for the regions that lacked the direct contact with one another. Afterward, satellites were launched to service the traveling users such as the military, ships, aircraft, and so on, and for supplying television programs internally (Maral & Bousquet, 2011). This was restricted to feeding cable head-ends in U.S., but direct-to-the home TVs has become widespread. Currently, the satellite service providers have realized a great opportunity in providing internet services to individuals and business users across the globe. According to Houssein (2013), the advancement in technology calls for faster and reliable internet connections. In the modern society, the internet usage is growing as well as the desire to produce quality web pages with animations videos online gaming, mobile applications and so forth. Therefore, the internet use in the future will be skewed for efficient, reliable and convenience sources that can support different wed based applications. Portable satellite internet 1. Portable satellite modem Portable modems are rectangular boxes and contain all apparatus for internet connection. Unlike the VSTA that can be placed in undefined direction, portable satellite modems are positioned to face the general direction of the satellite (Salkintzis, 2004). These modems are fitted with inbuilt signal strength meter that allows the user to locate the direction of the satellite. They have general connectors such as Ethernet and Universal Serial Bus (USB). An example of a portable modem is BGAN. These modems have internal batteries to prevent overconsumption of PCs battery. The portable modems are convenient to use especially in remote areas where other forms of internet connections are not available. They have a connection speed of between 350 to 500 kilobits per second. Initially, people used to access the internet from a fixed area especially in offices. This required internet that could allow large exchange of data (Kota, et.al, 200). However, in future people will be using the internet as individuals or in small size offices since most employers will opt for home based workers. This means in the future most internet users will be small clients thus portable modems using satellite will be sufficient for them. 2. Internet through satellite phone Phones connect to the internet through varying bandwidth of between 2400 bits per second for Iradium system satellites to an upstream of 15 Kbit/s and downstream of 60bit/s ACeS based phones for Thuraya model. According to Maral & Bousquet (2011), phones can be linked to laptops via RS-232 interfaces of USB. The phone internet dial-up is so slow thus making it hard for the user to browse websites. However, such internet can be used to send and receive emails. In the future, the providers of this internet will increase its performance thus increasing demand for satellite network as opposed to other sources of internet. 3. One-way receive, with terrestrial transmit This type of internet is used in conventional dial-up internet access with outbound data relayed via telephone modem while the inbound data is sent through a satellite at a faster rate (Houssein, 2013). One-way satellite is quite cheap because the user is charged depending on the volume of data exchanged. The mobile satellite broadband enables users to access the internet easily irrespective of the area. All they need is a GPRS notebook, a satellite dish and a GSM enabled mobile phone. 4. Two-Way Receive The Two-way satellite internet uses “Internet Protocol (IP) Multicasting Technology” that allows simultaneous multiple channels communication by a sole satellite IP by sending data from one region to another in a compressed format into a zip (Kota, et.al, 2004). Usual dial-up land-based terrestrial systems have limited capacity for bandwidth hence preventing multicasting. Therefore, Compression reduces the size of the data and the bandwidth. 5. Dial-up internet access The dial-up internet access uses telephone number to connect the user to public-switched telephone network via modem (Salkintzis, 2004). It is slow but very cheap. As more sophisticated phones join the market it is likely that the efficiency of this internet will increase thus increasing demand for the satellite internet. 6. Broadband ISDN This uses optic telephone lines to relay data. Some regions of the globe cannot be accessed using optic telephone lines and due to dispersion of the internet users it will not be possible for internet providers to link all internet users across the globe (Maral & Bousquet, 2011). Therefore, in the future satellite internet will be the best option for those people who cannot get access to the internet through any other method. 7. Digital subscriber line This uses telephone lines connected to the user premises to relay data using two-way line thus it one remain connected at all times. Satellite operates purely on digital data transmission thus in the future use of telephone lines for internet connection will decrease (Salkintzis, 2004). Furthermore, the use of telephone lines for internet connection is inappropriate for a globalized economy because there high cost involved in establishing a connection to different regions via telephone lines. In fact, it is not practical to connect some regions of the world using telephone lines. Other factors that will influence the future of Satellite systems and internet access Wireless internet connection is mostly available in metropolitan areas. The users can access wireless internet from anywhere as far as they are within the area supplied with this kind of internet connection (Houssein, 2013). On the other hand, satellite internet is available everywhere as long as one can afford to pay for it. Therefore, in the future many people will prefer satellite internet because there is no one who intends to remain fixed in one place. Since satellite internet is available in different forms that are portable and transferable without additional cost, many people have installed WI-FI in the cars since it is convenient to use irrespective of the location (Salkintzis, 2004). In addition, there is an increase in use of laptop computers, IPads and smart phones that are convenient to carry around. This is opposed to analog internet where users are restricted to particular places especially in the offices. Due to increase in use of portable computers and smart phones it is likely that in the future people will prefer satellite internet to other forms of internet. Although satellite internet is quite expensive compared to other forms of internet connection, it offers excellent services especially for the users in the remote areas where other forms of "internet such as Digital Subscriber Line (DSL) and cable modem" are not available (Kota, et.al, 2004). The two-way satellite Internet is a better choice because it provides full time internet connectivity unlike other sources of internet connection that utilizes dial-up processes. Satellite internet connection provides excellent Web browsing services and files download. However, satellite networks are not effective for interactive functions such as online gaming due to long latency unlike the land-based internet structures (Salkintzis, 2004). Therefore, in the future there is a possibility that the cost of using satellite internet will come down due to increase in efficiency of providing the services as more users subscribe for satellite internet hence making satellite internet more competitive. Another challenge facing satellite two-way geostationary-satellite internet connection is the prolonged during transmission and receiving of feedback. The signal makes two round trips between the transponders orbits and the earth surface (Maral & Bousquet, 2011). This movement is in addition to the land-based data transmission between the earth-based satellite structures and the recipient of the internet services. The movement is too slow in comparison to the time taken by the electromagnetic wave to relay the data via the earth-based satellite arrangement. The transmission of the signal via satellite internet connection is subject to solar and rain fade interferences. The degradation occurs during a heavy downpour while solar interference occurs occasionally and momentarily especially in the mid-March and towards the end of September when the sun and the satellite align in parallel for a short moment (Kota, et.al, 2004). However, it is possible that more efficient satellite components that are tolerant to all weather conditions will be developed, therefore, increasing the efficiency and demand of satellite internet in the future. Later on, there will be an increase in use of online services such as electronic banking (e-banking), e-medicine, online studies, home based employment opportunities and these will increase the need for private network connections for people in different localities (Houssein, 2013). In most areas that are not served by any other form network connection, they will find the use of satellite internet as the only option. This is because satellite internet is accessible to anyone irrespective of geographical location as long as they have all apparatus intact (Maral & Bousquet, 2011). All other type’s internet connections favor those who are close to metropolitans where wireless internet and telephone cables are available or in large institutions that can afford to provide private internet connection. Conclusion Satellite internet offers the users of the internet across the globe an opportunity to be connected with the rest of the world. The increase in use portable of gadgets such as IPads, smart phone and laptops will increase the use of internet by single users’ hence increasing demand for the satellite internet. Satellite internet will be convenient for this purpose because particular users will be scattered in different regions thus it will be very expensive to use other sources of the internet. Furthermore, the use of portable internet boxes will increase convenience for use of satellite internet since many people will prefer using their portable electronic gadgets in different locations. As technology improves, it is likely that the cost of providing satellite internet will decline drastically thus attracting more users. In addition, the new technology may result to improved satellite based components that can withstand different weather conditions and offer convenient and reliable internet connection. References Houssein, C. (2013). The Social Media Usage, Tahriib (Migration), and Settlement among Somali Refugees in France Refuge, Vol. 29(1): 32-58. Ibrahim, H. B. (2008). The Satellite Television and Public Sphere in Egypt: Is There a Link? Global Media Journal, Vol. 7(12):24-37. Kota, S., Pahlavan, K. & Leppanen, P. (2004). Broadband Satellite Communications for Internet Access. Kluwer Academic Publishers: 99-134. Maral, G. & Bousquet, M. (2011). Satellite Communications Systems: Systems, Techniques and Technology. U.K: John Wiley & Sons. Salkintzis, A. K. (2004). Mobile Internet: Enabling Technologies and Services. U.S: CRC Press: 4-6. Read More