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—The use of OVSF codes in WCDMA systems has offered opportunities to provide variable data rates to flexibly support applications with different bandwidth requirements. Two important issues in such an environment are the code placement problem and code replacement problem. The former may have significant impact on code utilization and, thus, code blocking(More)
In multihop wireless ad hoc networks, it is important that all mobile hosts are synchronized. Synchronization is necessary for power management and for frequency hopping spread spectrum (FHSS) operations. IEEE 802.11 standards specify a clock synchronization protocol but this protocol suffers from the scalability problem due to its inefficiency contention(More)
Packet scheduling in a WCDMA system poses a new challenge due to its nature of variable bit rates and location-dependent, time-varying channel conditions. In this work, two new downlink scheduling algorithms for a WCDMA base station are proposed to support multimedia transmissions. With a credit management and a compensation mechanism, our algorithms(More)
—In the third-generation partnership project technical specification, orthogonal variable spreading factor (OVSF) codes are used as channelization codes. The use of OVSF codes can provide variable data rates to flexibly support applications with different bandwidth requirements. Most works in the literature assume that only one single OVSF code is used to(More)
—In a cognitive radio network (CRN), two nodes have a rendezvous when they tune to the same channel simultaneously. Providing rendezvous guarantee between any pair of nodes is essential because a rendezvous is necessary for communication. Some existing works claim that rendezvous guarantee can be provided by using a dedicated common control channel to(More)
In this paper, the authors propose a power-saving protocol, the fuzzy control quorum-based energy conserving protocol (FQEC), for IEEE 802.11 ad hoc networks. In the IEEE 802.11 power saving mode, hosts have to wake up every beacon interval to check if they have to remain awake in the remaining of that beacon interval. It is not an efficient power-saving(More)