Ankara : The Department of Electrical and Electronics Engineering and the Graduate School of Engineering and Science of Bilkent University, 2012.Thesis (Master's) -- Bilkent University, 2012.Includes bibliographical references.In wireless networks, there are two main scheduling problems: uplink (mobile
station to base station) and downlink (base station to mobile station). During
the downlink scheduling, scheduler at the base station (BS) has access to queue
information of mobile stations (MS). On the other hand, for uplink scheduling,
BS only has the partial information of the MS since distributing the detailed
queue information from all MSs to BS creates significant overhead.
In this thesis, we propose a novel uplink scheduling algorithm for delay sensitive
traffic in broadband wireless networks. In this proposed algorithm, we
extend the bandwidth request/grant mechanism defined in IEEE 802.16 standard
and send two bandwidth requests instead of one: one greedy and the other
conservative requests. MSs dynamically update these bandwidth requests based
on their queue length and bandwidth assignment in previous frames. The scheduler
at the BS tries to allocate these bandwidth requests such that the system
achieves a high goodput (defined as the rate of error-free packets delivered within
a maximum allowed delay threshold) and bandwidth is allocated in a fair manner,
both in short term and in steady state. The proposed scheduling algorithm
can utilize the network resources higher than 95% of the downlink scheduling
algorithms that use the complete queue state information at the MS. Using just
partial queue state information, the proposed scheduling algorithm can achieve
more than 95% of the total goodput achieved by downlink scheduling algorithms
utilizing whole state information. The proposed algorithm also outperforms several
downlink scheduling algorithm in terms of short-term fairnessCoşkun, Cemil CanM.S