Performance Optimization in Rural Telephony - Term Paper Example

Name: Institution: Task: Date: Performance Optimization in Rural telephony Rural telephony has been a recurring subject for most large developing countries. It has been known for a long time that a country's economic development is strongly correlated to its telephone density. This situation is most evident in countries with a large rural population and a vast territorial area. These require a large investment in telecommunications equipment and also long implementation time. In most cases, satellite based telephone network provide efficient long distance telephone service to remote rural communities at lower cost than land based wired networks. Mobile Satellite Systems (MSS) have therefore been more preferred for this application. Their intrinsic nature comprised of high operational costs, circuit switched, low traffic capacity, has kept them away from rural telephony applications (F. Hernandez-Campos and F. D. Smith, 24) Research Goals The purpose of this research is to explore and define resourceful ways to provide economically friendly data transmission and digital telephone service to rural communities by means of a communications satellite. A comprehensive description and analysis of the current technology in use and that which has been developed to the convenience of serving rural communities with current systems or the need to do so. The Telephony Problem: Local and Long Distance Communications. Rural communities without telephone service have two different problems: they can neither make local calls nor long distance ones. If a rural village has at least a single long distance telephone line then at least communicate with relatives, other government offices or authorities. Although many countries mandate their local telecommunications operators to provide long distance telephone service these mandates are often delayed or ignored because of economic factors. Rural villages hardly have local service if they do not have long distance service, which has higher priority. Local telephone services are usually implemented in villages where a certain minimum size and telephone traffic conditions are met. Other conditions include familiarity of the locals with its use and after long distance service has been operational. A private network is that local network not connected to the Public Switched Telephone Network (PSTN). The local network's transmission media between the switch and the local user's premises is called the "last mile technology", and it may consist of cabled (wired) or radio (wireless) communication links. Local calls are handled by the local switch office. These connect calls from one villager to another rural subscriber depending on the number dialed. When a person dials a long distance number, the local rural office switches the call to the long distance switch. This is also referred to as the gateway which connects the call to the long distance transmission system. It then carries the call to another gateway connected to the PSTN. This is the reason long distance gateways are among the most significant elements of the telephone network regarding rural telephony. ‘It is the intention of this work to show that a satellite system can provide rural telephone service with a good Quality of Service a digital communications network. Special attention is drawn to the remote (rural) and gateway (urban) earth station elements and overall satellite network technology that provides long distance telephone service using Very Small Aperture Terminal (VSAT) technology when following a cost-efficient design methodology (R. Kalden and H. Ekstrom, 23)’ Design of Rural Telecommunications Networks There are several issues to be determined when designing rural telecommunication networks. All of these are of great importance and fall into three main areas: geopolitical, technical and economic. Geopolitical issues deal with the rural region's developmental level. This is generally based on the area’s social, educational, political and economic history. Technical issues on the other hand usually refer to evaluation of available technology, legal and regulatory frameworks, rural communities’ size and the type of communication services expected communications traffic and available technical workforce. Economic issues deals with defining the initial investment requirements to deploy for the communications equipment in a remote region. Its generally specializes within operational cost and the users’ revenue generating capacity, so that service is self supported financially and that subsidies are retained at their minimum. The latter analysis must include initial and future expected traffic, the cost of available technology and the performance metrics. It also deals with the technical standards required by the national telecommunications networks. The present work is mainly situated in these two areas, technical and economic. The economic analysis of the network is a mainly a finance problem in the specification of technical elements in communications networks. The proper network design sequence and future economic success depends heavily on systems engineering. The Life Cycle Process The systems engineering process provides a way to better understand and approach most design problems over the complete life cycle of a product, in this case a rural telecommunications network. It provides the methodology to efficiently manage any given manmade system, from the conceptual design to the termination and disposal stages. Based upon this approach, the design of any communications network must include the steps shown in The systems engineering life cycle process. To design a satellite rural communications network sequence of technical and economic activities is a complex process. It’s achieved by many people in different areas of expertise and at different times working as a team following a system management plan and supervised under a single authority. The key to the success of this systems engineering process is high-quality planning, teamwork and good management. The technical scope of the present work is only at the network design stage; thus the rest of the technical process is to be done elsewhere. The economic scope of this work must also the following steps in order to provide investors with a clear idea of all major financial milestones. 1. Network Planning Stage: This stage is basically involved with identification of rural telephone needs, determining the scope of the network problem and definition of possible solutions. 2. Network Design Stage: involves the search for real and feasible solutions once the basic needs have been identified. The input information must be processed with whatever technical and economic constraints exist, and optimal solutions are delivered. 3. Network Development Stage: This refers to the necessary steps to develop the network elements as defined at the design stage. Includes the logistics to acquire, assemble and deliver systems and subsystems, personnel training and testing. 4. Network Implementation Stage: This stage is concerned with the construction of the network following the previously defined logistics plan. It’s done by transporting the equipment to its final destination, assembly of systems and subsystems at each site, testing each terminal and local network, and finally training of local operators. 5. Network Operation Stage: This is the use of the communications network by rural users as initially specified in the conceptual stage. It refers to the delivery of the end product to the consumer. In this case, the digital telephone service to rural users and it should last through the expected equipment life cycle. It is also during this productive equipment’s lifetime that it will generate revenue to network operators and investors as defined in the network design stage. 6. Network Termination Stage: This stage is concerned with the retirement of equipment after it has reached its operational lifetime. Aging, frequent equipment malfunctions, new technology availability or high operational costs may be the cause of this. New regulations are being implemented to design a more environmentally friendly way to dispose of this equipment. Satellite Communications Concepts All satellite communication systems have two segments: the ground segment (earth stations) and the space segment (communications satellites). The ground segment may be further divided into two main elements: a transmit earth station and a receive earth station. There may be any possible combination of these elements: a single transmit/receive earth station operating on a closed loop, one transmit and many receive earth stations (broadcast), or any number of transmit/receive earth stations forming a satellite communications network. A network may be connected into a number of different topologies, depending upon its main application and technical requirements. Since the early 1960's the development of satellite communications has been impressive in terms of capacity as well as in performance satellite service is still subsidized at some point. Multiple Access and Topology Evaluation Techniques This is the process of optimizing the resources on a communications network. In this case, its the satellite channel where earth stations try to communicate through it. , the channel may be available to every one at all times depending on the network configuration, and especially on the expected earth station traffic. Different applications require different types of multiple access depending on the type, quantity and limitations of the information required. High traffic and High volume applications require fixed assignment at all times. Short volume applications or busty applications are more efficient on contention assignments. This is because Demand assignment is between when a channel may is required for large volume transmissions but only for a period of time. It releases the channel once it has finished using it. Multiple Access Techniques ‘There are various types of fixed assignment or basic access protocols: Frequency Division Multiple Access (FDMA), where each earth station is allocated a specific frequency and bandwidth on the satellite’s transponder at all times and no one else can use it, even when the frequency is idle. Time Division Multiple Access (TDMA), where each earth station is allocated the whole transponder bandwidth but only for a specific amount of time in a sequence, called a time slot. Code Division Multiple Access (CDMA), where each earth station may use the whole transponder bandwidth all the time, thus interfering with each other, but is assigned a specific orthogonal binary code so that only the desired receiving earth station can recover the transmitted information’ (T. Henderson and I. Abyzov, 112). References: T. Henderson, D. Kotz, and I. Abyzov, The Changing Usage of a Mature Campus-wide Wireless Network, in 10th International Conference on Mobile Computing and Networking, Philadelphia, PA, USA, 2004, pp. 187-201. F. Hernandez-Campos, K. Jeffay, and F. D. Smith, Tracking the Evolution of Web Traffic: 1995-2003, Orlando, FL, USA, 2003, pp. 16-25. R. Kalden and H. Ekstrom, Searching for mobilemice and elephants in GPRS networks. Comput. Commun. Rev., vol. 8, 2004, pp. 37- 46. Donald E.Thomas and Philip Moorby. The Verilog Hardware Description Language, Kluwer Academic Publishers. E Sternheim, R Singh, R Madhaven and Y Trivedi. Digital Design and Synthesis with Veriloged, Automata Publishers. G Russell, D J Kinniment, E G Chester and M R McLauchlano Designing Asics Read More