A Dynamic GTS Allocation Algorithm in IEEE 802.15.4 for QoS guaranteed Real-time Applications

Abstract

In this paper, we propose a novel QoS guaranteed algorithm for .4 standard provides a Guaranteed Time Slot (GTS) mechanism to allocate a specific duration within a superframe structure for time-critical transmissions. However, there are many weak points to support real-time applications. We suggest a new slot allocation algorithm that enables guaranteed services to be more efficient. The proposed algorithm also allocates a new guaranteed time slot dynamically to support real-time applications which have periodic messages. We evaluate the delay bounds and the throughput of the proposed scheme compared with original protocol. We then show that our proposal improves the bandwidth utilization and guarantees real-time features more strictly.

Performance Analysis of GTS Allocation in Beacon Enabled IEEE 802.15.4

“…When the maximum number of requests is greater than 7, the average delay is monotonically increasing, i.e., we see an unstable queue size because the maximum number of GTSs per superframe is 7. The monotonic relation between average delay and BO does not hold for BO = 2, 3 of the mean number of GTS requests (5,6). This behavior is explained by looking at the maximum number of GTSs ∆ u given by Eq.…”

“…Some interesting algorithm are proposed to improve the performance of GTS allocation mechanism. To maximize the bandwidth utilization, the smaller slot size and offline message scheduling algorithm are proposed in [4], [5] and [6], respectively. In [7], the delay constraint and bandwidth utilization are considered to design the GTS scheduling algorithm.…”

Traffic differentiation and dynamic duty cycle adaptation in IEEE 802.15.4 beacon enabled WSN for real-time applications

“…OPNET was chosen because of its precision and its advanced GUI (OPNET supports the use of modeling different sensorspecific hardware, such as physical-link transceivers and antennas) [21]. Other simulators such as ns-2 have been used to evaluate WSN, however since the MAC protocols, packet formats and energy models were originally built for IP-based networks and later extended for wireless ad-hoc networks the results can be less accurate [22,23].…”

An Innovative Alarming Access Strategy in the WBANs

“…ALGORITHM ANALYSIS We assume that all nodes are within the transmission range of each other and time-synchronized by the PAN coordinator's beacon. We assume that the frame arrival rate of each node T T T T T T T T T D t tdt T T tdt t tdt T T tdt T (12) In the AAC scheme, we assume that the slot-As uniformly distribute in the CFP. We also assume that there are no collisions in the slot-As.…”

“…In contrast with the amount of the wasted bandwidth, the rest nodes use the CSMA/CA algorithm to obtain channel and transmit packets (especially time-critical emergent packets) with a little probability. Similarly, to solve the bandwidth underutilization problem in GTSs, some new schemes to GTS allocation are proposed in [10][11][12][13][14][15].…”