We are using OPNET for:
 

Assignment of Nonblocking OVSF Codes, Rate Allocation/Detection and Bandwidth Scheduling in WCDMA

 

 

Multimedia traffic have different quality of service (QoS) requirements, power and rate constraints. The fact that third generation (3G) wireless systems are expected to support different services, data rates, and QoS requirements makes it necessary to have efficient radio resource allocation algorithms for adaptive power and rate transmission. WCDMA specifies four distinct QoS classes: conversational, streaming, interactive, and background. Adaptive rate transmission can be applied to the users of interactive service class because data is bursty in nature and their QoS requirements are very flexible in terms of delay and throughput. If there is no rate adaptation in downlink channels of WCDMA, then few high-speed data users with low activity factor can consume all available OVSF codes, leading to their inefficient usage. Fortunately, downlink shared channels can reduce downlink code consumption by sharing OVSF codes to support bursty traffic. Data rate adaptation for packet data service requires dynamic bandwidth management and burst allocation. The rate adaptation scheme must provide the receiver with the method of detecting a rate change. In this work, we will expand the capability of OPNET to simulate the data link and network layers of 3G systems for the proposed algorithms and nonblocking OVSF codes. The simulator SPW is used to simulate the physical layer of 3G systems for the proposed algorithms and nonblocking OVSF codes.