Detailed instructions on upgrading an 802.11n Wireless LAN

Wireless LAN, or WLAN, is essential for every enterprise in the future. So how to build a wireless LAN, how to use it, and how to maintain and upgrade the wireless LAN is what every administrator needs to know. The following article will introduce you in detail how to upgrade a wireless LAN.

Deploying an 802.11n access AP may be a huge task, but it is only part of a larger network upgrade. From higher speed and capacity to real-time application support and key tasks for enterprise network access, 802.11n increases the threshold for wireless LAN/WLAN. To enable 802.11n to achieve optimal performance, enterprises must plan new AP hardware, as well as new client devices, network architecture extensions, update management tools and training.

Upgrade the wireless LAN for the added workload

Upgrading an existing WLAN to a faster 802.11n AP requires more wireless control functions and backhaul network bandwidth. In addition, many businesses will use 802.11n to expand wireless services to support more users, new applications, and wider coverage. To avoid unexpected situations, we need to estimate the traffic load of wireless transmission in advance and its increase over time.

A typical 802.11a/B/g AP supports a maximum data transmission rate of 54 Mbps. Only half of the data is used to support application throughput due to overhead. Depending on the actual product and configuration, the Draft 2.0 802.11n AP can support a data transmission rate of up to 150 Mbps, And the + Mbps is the application throughput. Therefore, replacing the dual-RF conventional AP with an 802.11n standard AP may increase the maximum load supported from 54Mbps to 300 Mbps.

However, few WLAN will be immediately transferred to new clients and applications that fully use all wireless capacities. In the short term, a more practical plan is to use one wireless support for the 802.11g client, while the other supports the 802.11n client, so as to support the total throughput of up to Mbps.

Therefore, you may want to plan a network upgrade to increase the workload by four times on the WLAN controller, the link used to transmit traffic to the distribution network, and the distribution layer switch. This increase may increase after the client device is upgraded to 11n, so you can check the notebook and handheld device refresh cycle to estimate the flow of your working population over time.

Breaking through the bottleneck in upgrading Wireless LAN

When planning a wireless LAN, it is important to consider the installation and connection of the new 802.11n AP to the enterprise network.

Some new APs may be connected to the existing limited-capacity WLAN controller, while other APs require upgrading the controller of the wireless LAN, especially when the 802.11n is used to increase the coverage. In a specific location such as a small office), you may want to install an independent 802.11n AP that does not collect traffic through the local controller. In any case, WLAN design and configuration should be used to identify and eliminate potential bottlenecks. For example, routing WLAN traffic directly between APS can reduce latency and controller load.

Next, consider connecting the WLAN controller and independent AP) to the return link of the wired distribution network. Some 10/100 Ethernet links will eventually need to be upgraded to Gigabit Ethernet-if it is not between the Controller and the switch, it may be between the switch. In addition, you should consider using 802.11n for a 5 GHz Wireless return network-especially in areas where cabling is difficult, such as areas where new lines cannot or are not suitable for installation. Because of the larger capacity and faster transmission rate, 802.11n is more suitable for transmitting the return traffic typically transmitted by 10/100 Ethernet. But do not forget to perform AP redundancy to ensure the availability of the return operation.

Plan the added 802.11n power supply requirements

When running at the maximum load, 802.11n AP requires a larger power supply to drive their extra multi-Inbound and extra MIMO) sending/receiving chain and precise CPU. Enterprises that use standard 802.3af Power over Ethernet (PoE) to drive traditional AP will find that each port Power of a new 3x3 MIMO 802.11n AP will exceed 12.95.

Although the current AP implements a stable Draft 2.0 802.11n standard definition function, many APs are still the first to appear in the new generation of Enterprise WLAN products. Next year, the AP may be able to attract more efficient chips and find other methods to optimize power usage. Therefore, PoE may or may not be deployed on 802.11n, depending on the product you choose, the PoE-supported switch you use, and the way you configure WLAN.

Consult your supplier to estimate the PoE of the AP you selected under the specific configuration of the deployment plan. For example, if a dual-rf ap in 3x3 MIMO mode will exceed your power supply capacity, you can consider using one Wireless AP in 2x2 mode temporarily. You may not need to use all the possible loads of all new 802.11n APS immediately. Instead, you can plan to deploy more PoE ports when the switch is upgraded, and/or insert a relay power booster as needed.

Extended 802.11n management tools

Because 802.11n APs are new standards, they require upgrading Wireless LAN planning, monitoring, and troubleshooting tools. Existing WLAN tools can use certain 802.11n APS-for example, WLAN analyzer and wireless intrusion defense system WIPS) to detect 802.11n APS running in traditional or hybrid mode. However, these systems use traditional 802.11a/B/g Wireless RF terminals that cannot receive or fully decode signals sent by 802.11n improved technologies, such as 40 MHz bandwidth channels or frame aggregation. To implement the functions they have applied, these tools must be upgraded to support 802.11n.

As mentioned in "802.11n AP Deployment best practices", you can plan and upgrade a wireless LAN by using a predictive modeling tool for optimal performance and ROI. You need to purchase RF planning tools that support 802.11n features, MIMO signal transmission, and recommended location and options during the same period. In particular, when switching from a data WLAN with the best performance to a hybrid media WLAN with key services, use the planning tool to map users/devices to the effective scope of the application, so as to meet the specified service quality indicators.

During WLAN deployment, handheld tools must support signal scanning and connection debugging. These tools must not only be equipped with new 802.11n adapters, but also support subsequent changes to 802.11n. For example, a signal scanning tool can be used to measure not only the signal strength but also the application Throughput-and bidirectional. You must use diagnostic tools that accurately describe the 802.11n features and support mismatching instead of comparing PDU domains and bitmaps. Use the monitoring feature provided by the new 802.11n AP-they have a more continuous RF environment view and can record useful observed data when transmission problems occur.

Improve WLAN monitoring of 802.11n

After deployment, use a dedicated central security and performance monitoring system to focus on your larger and faster 802.11n network. 802.11n WLAN is more dynamic and uses technologies such as 3D diversity and dynamic frequency selection to bypass their own problems. However, when problems occur, they occur faster, affecting more users and more sensitive applications. The only effective solution to these problems is to maintain 24/7 of WLAN monitoring that supports rapid analysis and response.

For example, because 802.11n expands the coverage of WLAN, malicious and unexpected connections will increase. Upgrade the WIPS detector and the AP configured as the detector) to parse the 802.11n traffic and overwrite all affected areas. Configure an automatic response policy to block malicious intrusions, including 802.11n Greenfield AP ). Use multi-channel locating technology to quickly assess the impact of malicious intrusion and find them.

Finally, most companies will encounter real-time throughput and deployment of 802.11n improvement technologies. However, the 802.11n protocol and options are complex, and WLAN is impossible to run at maximum usage and operational efficiency without additional training and tool investment. Upgrade the RF performance monitoring tool to analyze and evaluate the 802.11n options-including not only general aspects, but also understanding the specific AP and client used in WLAN. Find tools that can recommend potential optimization methods and help administrators visually modify possible impact-and implement them through automatic configuration update and release.

Although these network and management architecture updates are not strictly mandatory during the migration to 802.11n, they are a reasonable investment. Upgrading to 802.11n, regardless of network capacity, visualization, and control functions, is as dangerous as driving a high-speed sports car with blurred windshields and brake failures to a narrow mountain road. Planning your WLAN with the right tools can avoid dangerous accidents and increase the probability of successful network transplantation.