Wireless Network Planning and Management Analysis (1)

For enterprise wireless LAN, on the one hand, we need to deploy a variety of wireless devices and consider coverage. On the other hand, application and security also pose challenges to the management of wireless networks. The Planning and Management before and after the establishment of the wireless network are the real lubricants available for the wireless network.

The so-called great difficulty is that enterprise wireless LAN generally has a large scale. It is not a simple combination of wireless products, but an overall enterprise system. The wireless LAN system must meet the expansion needs of enterprises to ensure high throughput, secure mobility, and seamless integration with wired networks. In many cases, a wireless LAN composed of an access point is simple, but when a second access point needs to be expanded to support more users, its complexity will suddenly increase.

When there is only one access point, roaming is not a problem. You can select a wireless channel at will. As long as the connection is not interrupted, you will not care about its performance. However, once expanded to the enterprise level, there will be many problems. Therefore, during deployment, a method with a more reasonable structure and good scalability must be adopted, and the architecture and scalability of applications in the wired network infrastructure should be used to build a wireless network.

First, we must weigh the trade-off between wireless network capacity and coverage. A wireless LAN is essentially a shared network, but users want applications on a wireless LAN to be as responsive as they are on a switched network, and want additional benefits, such as mobility, from wireless networks. Enterprise IT managers must design a shared wireless network that ensures the mobility required by users and provides application responsiveness they expect. Many designers mistakenly focus only on providing sufficient coverage for users, rather than on providing sufficient bandwidth. Although the coverage of an AP-based network for a conference room or working group may be the starting point of the design, the application requirements of enterprises make the bandwidth capacity a real design standard. The principle is very simple. If it is designed only for coverage, it cannot provide enough bandwidth.

Key considerations for deploying a wireless LAN include identifying RF coverage for a single access point, ensuring sufficient capacity for all users, and considering RF signal loss factors. The number of users and their applications are the main factors driving the increase in bandwidth demand. During network planning, you must consider the number of users in the AP cell diameter. In a large office or environment with a high user density, small cells should be designed to achieve a higher data rate, because walls and other items will not naturally limit the scope of these cells. When using a small cell, you need to reuse the frequency more often to ensure that the channels do not overlap.

Secondly, it is necessary to explore the real performance of wireless networks out of support for various applications. Determining the amount of bandwidth required by each user is a key task, because your computing determines the user's experience and the number of access points required. An effective rule for 802.11a and 802.11g networks is to allocate 2 Mbps downstream bandwidth and upstream bandwidth (4 Mbps in total) to each user ), this bandwidth provides the same experience as the user on a wired LAN. For 802.11b networks, the empirical rule is to allocate 500 Kbps (1 Mbps in total) in each direction, which can provide users with experience similar to broadband DSL connections. The impact of user applications on radio activities should also be considered. Radio activity occurs when the user sends and receives data. Reading web pages does not require any radio activity. However, a large enterprise resource planning or customer relationship management application may cause a lot of interaction between the client and the server, it will also lead to much more radio activities than office applications.

The main difference between planned wired LAN and wireless LAN is the loss of radio signals caused by the attenuation of walls, doors and windows, and other fixed objects in buildings. If an enterprise wants to build an 802.11b/11G wireless network, it should avoid placing the access point within several feet of the 2-4 GHz frequency band equipment, while 802.11a is running on 5 GHz, therefore, there are many fewer interference problems.

After determining the network performance, the next step is to determine the size of the coverage area of the wireless LAN through the width and length of the coverage area of the wireless LAN. An office building can be divided into multiple parts for design. For example, the project department can be designed separately because the project department requires more bandwidth than the office applications of sales and marketing personnel. It can be designed independently of other parts of the enterprise for hotspot areas (such as conference rooms), because hotspot areas have different access and service quality requirements.