ith additional space for simultaneous voice and data. The standard is going to mandate either the use of MIMO (multiple input/multiple output) techniques to get throughputs of up to 100 Mbit/s and/or the Interrelationship of the Physical Layer with Other Layers of the OSI Model use of channel bonding. The headline data rate for two adjacent 'bonded' 40 MHz channels is 250 Mbit/s. The MAC overheads bring this down to about 175 Mbit/s. 3.5.8 802.11 S Mesh Networking Finally (for the moment), 802.11s addresses mesh networking and ad hoc network protocols. This potentially brings WiFi into much more direct competition with Bluetooth-based personal area networks (PANS) and device access/device area networks (DANS). Mesh networking protocols may also facilitate a whole new generation of wearable WiFi products both for consumers and professional users. 3.6 The WiFi PHY and MAC Relationship As a reminder, an 802.11 b and g access point will typically be configured in the 2.4-GHz ISM band to support 3 nonoverlapping 20 MHz radio channels with centre frequencies spaced either 30 MHz apart (Europe, Channels 1, 7 and 13) or 25 MHz apart (channels 1, 6 and 11 in the US). Access points using the 5-GHz ISM band (802.11 a) will typically be configured to support up to 8 channels spaced 20 MHz apart (Europe Band 1 and US Band 1 and 2), with additional channels available in Band 2 in Europe and Band 3 in the US. Raw data rates of 54 Mbits/second are achievable in strong C/I conditions using high-level modulation and an OFDM multiplex to improve channel resilience. Multiple channels capable of supporting multiple users cosharing a common 54 Mbps looks like a lot of bandwidth, but in practice there are significant MAC overheads and link budget constraints that result in substantially lower net throughput rates. These MAC overheads increase when periodic two-way time-bounded services for example real-time voice and/or real-time voice and video need to be supported alongside best-effort services. 3.6.1 Voice and Video Frame Lengths an