Wireless wlan ap must be upgraded When a mobile terminal joins the network

The current network structure is quite complex, and more mobile terminals are added to the network. Then, the wireless wlan ap can be upgraded in time to meet new requirements. Previously, 802.11a/B/g WLAN was only used for basic connections: to allow employees and visitors to access public Web and email services in an open area. Even later, the newer WLAN only supports business applications in a small range of target fields. But now these traditional WLAN must deal with more complex mobile services and mobile device connections. To establish a WLAN to process mobile data, voice and video services, the old 802.11a/B/g WLAN must be upgraded. In particular, the WLAN used to support mobile applications must also be based on the 802.11n technology and be designed to support greater speed, capacity, coverage, and reliability. This article focuses on how to design and upgrade wireless wlan ap for mobile services and applications.

Designing WLAN for mobile services and applications also requires a focus on the infrastructure

After you upgrade a wlan ap to 802.11n, your larger, faster, and more stable wireless network will support many different applications, including those related to mobile Unified Communication. However, the use of 802.11n technology itself cannot guarantee success-next-generation WLAN should take mobility into account in design, deployment, and management.

Planning: Traditional WLAN generally only provides limited VoIP support because they do not meet the needs of speech coverage and quality. The AP must be correctly installed to ensure seamless coverage for high-quality calls.

An AP must be installed at least-65 dBm at a minimum interval meeting supplier specifications. To achieve a cost-effective WLAN that supports a large number of devices and applications, we need to use predictable planning tools to transform complex coverage and performance goals into an optimal AP layout.

Priority: by combining 802.11n and 802.11e QoS, the Modern AP can transmit high-quality videos and implement interactive messages, leave sufficient bandwidth for sensitive speech traffic to be delayed. To achieve this, we must design an aggregation WLAN to use Wi-Fi MultimediaWMM) to set the voice transmission priority over video transmission, and the video transmission priority over the best state data. Then, these wireless priorities must be identified by using appropriate technologies to map prioritized mobile traffic to wired network QoS, such as 802.1p and DSCP.

In addition, we also need to know other features that can better allocate limited resources, such as converting a 802.11 a/n Notebook to 5 GHz, this can reduce the congestion of busy 802.11 GHz channels used by 2.4 B/g voice handheld devices.

Call Access Control: even in an 802.11n WLAN, shared bandwidth usage is limited. The WLAN that supports voice should use call access control to limit the number of active mobile voice sessions and balance deny or redirect excessive requests that may reduce QoS. For example, you may reserve a certain proportion of channel capacity for all voice calls, some of which are reserved for maintaining roaming voice sessions. Some wireless clients can also use the 802.11e Transmission Specification (TSPEC) parameter to submit reservation requests, such as data speed, split size, and service interval, so as to report in advance the desired bandwidth usage.

Energy-saving: 802.11 of devices running real-time applications powered by batteries encounter a tricky problem: they must communicate frequently without consuming too much power. Laptops used to check emails or access the Internet may sleep occasionally to save power. During these energy-saving periods, the AP automatically queues wireless traffic for subsequent connections. However, voice handheld devices do not support transient sleep, as do laptops running real-time wireless applications.

To solve this problem, we need to deploy a new 802.11 client that supports WMM Power Save. This standard mechanism enables sleep client requests to queue traffic without waiting for their scheduled wake-up calls, this increases the battery life by 40% without causing unacceptable latency for real-time applications.

Seamless Roaming: in fact, latency between delayed packets), jitter delay changes), and packet loss are important benchmarks for voice quality measurement. VoIP QoS should be taken into account in the design of an aggregated WLAN. WMM priority assignment and call access control should be used to meet these requirements for each call. However, changing the location of a mobile user in a session will make the problem more complicated-it is related to the topology, which includes roaming between AP or subnet. When upgrading a wireless wlan ap, We need to select a controller that supports fast switchover between 802.11i and/or 802.11r and that can maintain the Client IP address when completing a subnet roaming without exceeding the VoIP delay time.

Typical VoIP requirements

Redundancy: no matter what your expected application mixing degree is, more business processes support moving, making your business more dependent on your WLAN. Use Modern WLAN hardware features to design and create your high-availability wireless network, such as redundant AP, radio, return link, dynamic frequency selection, and dynamic power control. However, VoIP requires stability, so we need to focus more on tolerating Channel Changes or AP errors. For example, if a controller rapidly adds power to start the AP to fill the original coverage of the dead AP, it may affect the voice call that is still in progress. Therefore, you need to select the solutions that perform automatic wireless startup and slow frequency changes or consider active calls.

Service Guarantee: At last, every network that supports key tasks requires technical monitoring and proactive troubleshooting. Deploy tools and processes around your upgraded WLAN to monitor, detect, and respond to wireless network operation, security, and performance events.

Deploy a wireless IPS supporting 802.11n to continuously monitor RF usage and interference, as well as automatic end-to-end testing tools to regularly measure throughput, latency, and voice quality. Expand the wired network operation and help station process to repair WLAN faults, and purchase tools to quickly locate or eliminate wireless problems. This may increase the initial deployment cost, but it will also significantly reduce the operation cost. In a well-designed WLAN, most help station calls do not require expensive RF experts to handle, and quick problem identification will speed up problem resolution and reduce the impact on the business.

Upgrade mobile clients to support mobile services

Upgrading your WLAN infrastructure to support a greater degree of mixing of data, voice and video services is a good start, but to fully implement this, you must also upgrade the wireless client. Evaluate legacy wireless devices, plan their 802.11n upgrades, and budget for purchasing new wireless devices for mobile apps that support enhancements.

For example, most enterprise laptops enter the device update cycle at least a year ago, and they will upgrade the built-in WLAN adapter to 802.11n. Your wireless devices are likely to upgrade the wireless wlan ap and other related work in a short period of time, and start to directly use 802.11n to support mobile applications, such as video conferencing and teleconference.

On the other hand, the current wireless VoIP devices-including single-mode handheld devices that only support 802.11 to dual-mode smart phones that support Wi-Fi/3G-do not yet use the 802.11n wireless standard. The old 802.11b VoIP devices can be eliminated to reduce the change of the entire WLAN. When the new 802.11n customers are quickly switched to the 5 GHz band, 802.11n AP is used to support legacy 802.11g VoIP clients in the GHz band.

Finally, consider whether and how to use new wireless devices to improve device mobility, including common 802.11n media servers and 802.11n network storage devices, and 802.11n handheld media players and Wi-Fi/3G dual-mode netbooks. A reliable high-capacity WLAN not only expands business applications, but also makes good use of innovative client devices to achieve more efficient services of the same type for mobile users.