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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)
—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)
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)
Power saving is a critical issue in wireless sensor networks since sensor nodes are battery-powered. Data aggregation is an effective approach to save energy because the number of transmissions can be reduced after aggregation. In the literature, most of the data aggregation protocols rely on a structured architecture to accomplish data gathering. Such(More)
The lifetime of a mobile ad hoc network (MANET) depends on the durability of the battery resource of the mobile hosts. Earlier research has proposed several routing protocols specifically on MANET, but most studies have not fo-cused on the limitations of battery resource. This study proposes a new energy-aware routing protocol, which can increase the(More)