| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 5.48 MB | Adobe PDF |
Advisor(s)
Abstract(s)
The IEEE 802.15.4 has been adopted as a communication protocol standard for Low-Rate Wireless Private Area Networks (LRWPANs).
While it appears as a promising candidate solution for Wireless Sensor Networks (WSNs), its adequacy must be carefully evaluated.
In this paper, we analyze the performance limits of the slotted CSMA/CA medium access control (MAC) mechanism in the beacon-enabled
mode for broadcast transmissions in WSNs. The motivation for evaluating the beacon-enabled mode is due to its flexibility and potential for
WSN applications as compared to the non-beacon enabled mode. Our analysis is based on an accurate simulation model of the slotted
CSMA/CA mechanism on top of a realistic physical layer, with respect to the IEEE 802.15.4 standard specification. The performance of the
slotted CSMA/CA is evaluated and analyzed for different network settings to understand the impact of the protocol attributes (superframe order,
beacon order and backoff exponent), the number of nodes and the data frame size on the network performance, namely in terms of throughput (S),
average delay (D) and probability of success (Ps). We also analytically evaluate the impact of the slotted CSMA/CA overheads on the saturation
throughput. We introduce the concept of utility (U) as a combination of two or more metrics, to determine the best offered load range for an optimal
behavior of the network. We show that the optimal network performance using slotted CSMA/CA occurs in the range of 35% to 60% with
respect to an utility function proportional to the network throughput (S) divided by the average delay (D).