Link design and capacity comparison for burst transmissions of ATM cells and AAL PDU’s over broadband satellites

Broadband satellite will be an important element in the future Broadband Integrated Service Digital Networks (B-ISDNs) employing Asynchronous Transfer Mode (ATM) for connecting different B-ISDN islands. The main challenge is to maximize traffic capacity while meeting the diverse Quality of Service (QoS) requirements of different types of B-ISDN service. Furthermore, inefficient utilization of transponder power and/or bandwidth and reduced traffic capacity may be caused by link designs that satisfy the most stringent QoS requirements of the traffic mix. Different Forward Error Correction (FEC) coding techniques are thus investigated to optimize the satellite link designs for any given B-ISDN service. Four concatenated codes (CCs) have been chosen, employing an inner convolutional code, in concatenation with one of the four alternate short Reed-Solomon (RS) outer codes for evaluations. Furthermore, a novel partially-concatenated code (PCC) method is proposed to improve bandwidth efficiency without significantly reducing power efficiency. A PCC with RS(15,10) outer code is determined to be the best combination by balancing the trade-offs between error performance and ability to encode a single ATM cell. In addition, ATM Adaptation Layer Protocol Data Units (AAL PDUs) are considered to be transmitted directly into a physical medium without segmenting into ATM cells. In this way, traffic capacity may be increased. Finally, given all the relevant parameters, link budgets can be used to obtain the traffic capacities for different services. From the traffic capacity analysis, AAL PDU transport provides a capacity increase of at least 10% over that of. the ATM cell transport. This result indicates that AAL PDU transport may be considered as an alternate means for transmitting data over Broadband Satellite Networks (BSNs).Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat