Browse Prior Art Database

METHOD TO IMPROVE PACKET DATA BANDWIDTH EFFICIENCY IN A MULTI-SERVICE SYSTEM

IP.com Disclosure Number: IPCOM000008333D
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2002-Jun-06
Document File: 2 page(s) / 97K

Publishing Venue

Motorola

Related People

Robert C. Scheibel, Jr.: AUTHOR [+2]

Abstract

Many wireless communications systems today are adding packet data to the suite of services offered on one network. In these systems, packet data must share the available bandwidth with other (often circuit-switched voice) services. This requires (a) an algorithm for allocating bandwidth efficiently among the various services, and (b) a signalling protocol in a control channel to notify the subscriber units of changes to the bandwidth alloca- tion. This invention improves the efficiency of dynamic channel allocation when considering half- duplex radios.

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Technical Developments

METHOD TO IMPROVE PACKET DATA BANDWIDTH EFFICIENCY IN A MULTI-SERVICE SYSTEM

by Robert C. Scheibel, Jr. and Mark Peters

ABSTRACT

  Many wireless communications systems today are adding packet data to the suite of services offered on one network. In these systems, packet data must share the available bandwidth with other (often circuit-switched voice) services. This requires (a) an algorithm for allocating bandwidth efficiently among the various services, and (b) a signalling protocol in a control channel to notify the subscriber units of changes to the bandwidth alloca- tion. This invention improves the efficiency of dynamic channel allocation when considering half- duplex radios.

DESCRIPTION OF PROBLEM

  Packet data services are often offered as an additional feature to TDMA systems offering voice telecommunications as the primary service. Many of these types of systems use half-duplex radios. This solution is more economical than using full-duplex radios, and can still provide full-duplex service to the application layer. Full-duplex voice service is achieved by shifting the inbound and outbound time slots such that no overlap occurs. Figure 1 illustrates this concept. Notice that inbound time slot x does not overlap with outbound time slot x. Thus, each user can transmit one inbound burst and one outbound burst every TDMA frame, providing full-duplex voice traffic, even though the underlying hardware is half-duplex.

  Many packet data systems use all available slots to create one larger capacity multiple access channel. This constrains the flow of half-duplex subscribers; the network and transport layers are still offered "full-duplex" trafftc, but must suffer an additional delay in certain cases. Often, the shifting of inbound and outbound time slots is such that two inbound time slots overlap with each outbound time slot, and vice versa. This means that to receive an

outbound time slot, a half-duplex subscriber unit must not transmit i...