New delay-efficient TDMA-based distributed schedule in wireless mesh networks

Abstract

Time division multiple access (TDMA)-based medium access control (MAC) protocols can guarantee quality of service (QoS) in wireless environments. However, in an environment where multihop packet transmissions are necessary for real-time communications, each node may experience the well-known queuing delay. This queuing delay increases multihop packet transmission delay, resulting in not meeting the delay bound of real-time applications in multihop wireless networks. This article first introduces two kinds of queuing delays that can occur in multihop wireless networks. Then, this article proposes a new delay-efficient TDMA-based distributed scheduling scheme to eliminate the secondary queuing delay. For the performance analysis of the proposed scheme, the scheduling overhead is first evaluated in terms of power consumption. Next, the multihop packet transmission delay of the proposed scheduling scheme is derived and validated through a simulation, before comparing the result with that of the conventional minimum length scheduling scheme which employs distance-2 graph coloring. According to the simulation and analysis results, for a deterministic packet arrival, the proposed scheme works well irrespective of the packet interarrival rate and outperforms the conventional graph coloring. However, in case of a non-deterministic packet arrival, the multihop packet transmission delay of the proposed scheme is slightly higher than that of the conventional graph coloring because the probability that each node has more than two packets increases at the beginning of the frame. However, the multihop packet transmission delay of the conventional graph coloring is intolerable when the packet interarrival rate is high.

RMTS: A Novel Approach to Transmission Scheduling in Ad Hoc Networks by Salvaging Unused Slot Transmission Assignments

“…The nodes are capable of detecting and resolving any conflicts that arise from their requested slot assignments. In [14] the authors propose a delay efficient scheme where the slots are assigned to a traffic flow. The idea behind this approach is that the nodes in a particular flow are assigned adjacent slots in a frame so that once a packet leaves the first node in the frame it does not undergo any further queuing delay.…”

Mathematical model for resource allocation in TDMA-based wireless meshnetworks

“…As compared to wired networks, in wireless multihop mesh-networks the situation with delays is much more complicated. It caused by two types of delays [2]. First type is conventional queuing delay that is related to difference between rates of packet arriving into node and packet transmission (service) through outgoing interface.…”

“…First type is conventional queuing delay that is related to difference between rates of packet arriving into node and packet transmission (service) through outgoing interface. In work [2] the delay is referred to as primary delay. But secondary delay is related to use of slots to carry packets.…”

“…The standards and other described in literature approaches are based on different algorithms to share and compete in common resources. Depending on type of shared resources within WMNs time-division, code-division and space-division multiple access fashions (TDMA, CDMA and SDMA respectively) are used [1][2][3]. As it's shown in [2] TDMA scheduling scheme is more preferable from viewpoint of quality of service (QoS).…”

“…Depending on type of shared resources within WMNs time-division, code-division and space-division multiple access fashions (TDMA, CDMA and SDMA respectively) are used [1][2][3]. As it's shown in [2] TDMA scheduling scheme is more preferable from viewpoint of quality of service (QoS). Whereas problem of rendering of guaranteed quality of service is the urgent for next-generation communications systems, particularly for supporting real-time applications such as voice and video calls, in the article we'll focus on TDMA-based WMNs.…”