802.11n WLAN infrastructure strategy: 2.4 vs. 5 GHz bandwidth battle

Although 802.11n technology has enabled wireless LAN (WLAN) to reach unprecedented speeds, capacity is not the only way to address network performance. It is just as important to deploy an innovative 802.11n WLAN infrastructure and activate multi-channel auto-distribution to support the growing number of customers and applications on the network. Farpoint Group can test the importance of 802.11n WLAN infrastructure innovation and bandwidth allocation by testing Cisco BandSelect, a feature on the company's wireless controller that guarantees the client's 5GHz bandwidth as much as possible. Specifically, the test focused on speed, 11n and 11g synchronization on the same channel, and functional differences between 2.4 and 5 GHz bandwidth, especially when using 40MHz channels.

According to the approved final 802.11n standard, most people believe that the legacy of wireless LAN performance has been resolved. After all, 802.11n, a product model validated by the 2007 Draft Specification from the Wi-Fi Alliance, has been in use for some time. Most of these products offer basic 300 Mbps transmission performance, while products with transmission performance of 450 and 600 Mbps are also available. Achieving (Layer 7) single-client performance far exceeds 150 Mbps is commonplace, and because of the overall system performance improvements brought by 802.11n, especially the infrastructure innovations implemented by WLAN system vendors, .11n will It is expected to have a broad impact on all important application areas in the next few years.

Of course, .11n has not yet reached the 1 Gbps level, although we do not expect this to be the reason for replacing 802.11n, but the IEEE 802.11 organization is currently equipped with two additional task groups. (.11ac and .11ad) to achieve performance at this level and above. So no matter what, one of them might be able to try the new standard features and once again declare that there is no need to use more advanced methods to improve throughput, and more importantly, the capacity of the wireless LAN network, but people should be more cautious when applying this method —— In fact, Farpoint Group believes that this approach is completely wrong.

The reason for this problem is not very subtle. From the beginning, the demand for the network has always grown over time. The growing demand is reflected in the growing number of clients and the ever-increasing demand for applications, not just for throughput but also for time constraints, responsiveness and network-wide capacity. Although the throughput embodied by 802.11n is the most popular, it is not enough for enterprise-level performance. —— at least the innovative infrastructure from WLAN system vendors The right deployment is just as important. Finally, keep in mind that access to any given 802.11 channel is serialized, and this channel competition is often a factor in the performance achieved. Therefore, it is well suited to maximize the use of limited wireless resources, and wireless signals often fail to meet system-level infrastructure approaches and innovations. Therefore, just being powerful doesn't solve all the problems.

Therefore, this challenge introduces another development project for Farpoint Group Tech Note. In particular, we can examine the importance of the wireless LAN system infrastructure in configuring an optimal 802.11n-based solution. However, it is difficult to directly examine the advantages of a given infrastructure because the specific details of the specified implementation are quite complex. Therefore, we decided to conduct a few tests on a specific (and very popular) implementation to evaluate a specific infrastructure function —— for example, the functionality of Cisco BandSelect