te with node B, and node B can communicate with node C. However, node A cannot communicate node C. Thus, for instance, although node A may sense the channel to be clear, node C may in fact be transmitting to node B. The 802.11 protocol alerts node A that node B is busy, and hence it must wait before transmitting its packet. There are seven IEEE 802.11 subset standards (802.1 through 802.11g) as follows: 802.11a-Uses orthogonal frequency division multiplex (OFDM) modulation in the 5-GHz band supporting data rates from 6 to 54 Mbps. 802.11b-Provides high-rate direct-sequence spread-spectrum (DSSS) service in the 2.4-GHz band supporting 5.5 and 11 Mbps in addition to the 1- and 2-Mbps oper- ation. It uses complementary code keying (CCK) for more efficient use of the radio-frequency spectrum. 802.11c-Bridge operation procedure. 802.11d-Global harmonization to support widespread adoption in many countries. 802.11e-MAC enhancements for QoS. METROPOLITAN AREA NETWORKS 1802.11f-Inter-access point protocol, users roaming from one access point to another. 802.11g-Higher rate extensions in the 2.4-GHz band. 13.5 IEEE 802.15 STANDARD IEEE 802.15 is commonly called wireless personal area network or WPAN. Bluetooth WPAN and IEEE 802.15.1 refer to the specific, single example of a WPAN presented in the reference IEEE 802.15 standard. The WPAN technology can encompass the control of personal electronic devices such as notebooks, computers, cellular phones, personal digital assistants (PDAs), personal solid-state music players, and digital cameras, among many others. They currently all have increased data capabilities. Interconnecting personal devices is different from connecting computing devices. Typ- ically, connectivity solutions for computing devices (e.g., a WLAN connectivity solution for a notebook computer) associate the user of the device with the data services avail- able on, for instance, a corporate Ethernet-based intranet. This situation contrasts with the intimate, personal nature of a wireless connectivity solution