Avoiding Variability

Although the 5GHz band offers multiple 40MHz-wide channels, the reality is that many deployment scenarios will require some form of cell-planning, which presents a challenge given the unpredictable coverage caused by MIMO. The figure below shows how a cell-based solution is prevented from creating a predictable coverage environment. Each AP will have sporadic and changing coverage, which will inevitably impact other APs using the same channel.

  

Extricom is the only technology immune to cell-induced problems and variability of MIMO coverage. In fact, because MIMO improvements are opportunistic, the Extricom architecture actually improves MIMO performance by providing the "best" MIMO path on a packet-by-packet basis to a wireless client, thus adding robustness and stability to a highly variable technology. MIMO doesn't mess up your cell plan, because there's no cell plan to mess up! 

Are There Enough Channels in 5GHz?

The greater signal range enabled by MIMO can create a problem for cell planning at 5GHz. That's because an increase in overall range will in turn cause the range of the Clear Channel Assessment (CCA) to expand, which means that over-the-air contention between APs on the same channel will multiply.

There is little doubt that this will impact performance in the 5GHz band. While this band has a larger number of double-wide channels available, the ballooning of the CCA range will lead organizations to discover that cell-based WLAN architectures quickly eat into this pool of channels in an attempt to achieve frequency re-use.

Only the Extricom WLAN architecture is not subject to this performance issue. By definition, the Channel Blanket does not require cell planning, and ultimately results in a system with far more efficient use of each and every available channel. The elimination of cell planning, and all of the side-effects it causes, leads enterprises to a higher-performing and lower cost-per-port solution in total.

For more details on how Extricom 802.11n WLAN enables the full promise of 802.11n performance without a disruptive implementation, download Extricom's 802.11n Application Brief .