Table 1: Comparison of MAC parameters between beacon-enabled IEEE 802.15.4 and IEEE 802.11b.

CSMA-CA parameterIEEE 802.15.4IEEE 802.11b

Backoff period size320 s20 s
Listen to the medium during backoff countnoyes
Freeze the backoff ctr. when medium is busynoyes
Listen to the medium immediately before the trans.yesno
Action when medium is sensed busyNew backoff phaseFreeze the backoff ctr.
Typical size of minimum backoff window832
Typical number of backoff phases 55
Raw data rate250 Kbps1, 2, 5.5 or 11 Mbps
Typical physical + MAC layer header size48 + 72 bits192 + 272 bits
RTS and CTSNo in beacon enabled versionYes