Avi Barda, Zvi Ner, Shaul Laufer
Shiron Satellite Communications (1996) Ltd.

23 Hasivim St., PO Box 7567
Petach Tikva 49170
Israel

Abstract

It is only after access to technology is assured that computer literacy can begin. Access is not simply having access to up-to-date technology; it should also include access to qualified teachers, appropriate software and Web content. Vital to this issue is the quality and quantity of the access.

The optimisation of the bandwidth use, obtained by implementing bandwidth allocation schemes and suited protocol solutions, will allow providing improved quality of service and reduced cost of broadband Internet access. This technology will allow the provision of QoS-based broadband services in hazardous environments and in areas where the technological development is less spread and the Internet isn’t well delivered.

Resource allocation has become the most important technology in satellite and wireless networks. All satellite systems are limited by bandwidth and power, which are both expensive resources. Operators of satellite systems receive fixed allocations of these resources and as a result, are limited in the number of users they can support on one system. To combat this problem and to lower the costs for system operators, certain power and bandwidth conservation methods have been developed.

In the past, satellite systems were used to deliver telephony or transaction-based applications. Since telephony is a single application with a predefined bandwidth requirement, a simple resource allocation technique such as Demand Assigned Multiple Access (DAMA) is sufficient. A transaction-based application requires a simple ALOHA channel.

The development of Two-Way IP access systems, which support a variety of protocols and applications, has created the need for more complex resource allocation algorithms. Faced with a combination of real-time applications, such as Voice over IP, and non real-time applications that still require high bandwidth, such as e-mail transmission, resource allocation algorithms have had to work with two conflicting issues: Quality of Service and bandwidth consumption. As a result, Bandwidth On Demand (BOD) algorithms were developed to manage resource allocation and Quality of Service mechanisms were developed to identify the needs of different applications.

This paper discusses the application of different resource allocation algorithms to different type of traffic. Using mathematical formulation it presents the bandwidth saving achieved by BOD for IP type of traffic.