Cisco clambers aboard gig Wi-Fi bandwagon

Cisco has joined the growing list of vendors putting the 802.11ac “gigabit WiFi” standard into live kit, launching a “Wave 1” module for it Aironet 3600 series of access points, and promising “Wave 2” support in a future upgrade module.

The current kit, quoth the Borg, supports WiFi speed up to 1.3 Gbps, which in deployment means wireless networks will be able to support greater numbers of devices at better-than-limping per-user bandwidth.

Cisco has sewn some marvellous confusion in the press with its announcement, which red-herrings WiFi network speed with discussion of mobile traffic growth.

But the import of 802.11ac in enterprise, particularly campus environments, is its main appeal, something highlighted by Cisco's drawing attention to a hospital and a university as early buyers.

A big difference between 802.11ac and its predecessor 802.11n is that the newer standard can operate multi-user multiple-input and multiple-output schemes (MIMO). An 802.11n system would devote all of the MIMO paths to a single access-point-to-user communication, while 802.11ac can split the antenna paths between users (trading off single-user speed for higher capacity).

The 5GHz-band 802.11ac Wave 1 kit gets its top speed operating at its full carrier bandwidth of 80 MHz, with 20 MHz and 40 MHz slices also supported, and supports up to three spatial streams (that is, three MIMO transmission paths). The Wave 2 kit will add optional 160 MHz channel width, or paired 80 + 80 MHz channels. Its physical layer link speed is specified at above 3 Gbps. ®