Smart load balancing - knowing each other in Wireless space and better roaming

Introduction

Wireless Is Great, Except When It Isn’t

One of the challenges of WiFi is that clients are notoriously self-interested and use a very rudimentary decision making process to determine which AP to connect to. This decision is simply based on AP signal strength or signal-to-noise ratio (SNR). The IEEE 802.11k standard is designed to help the clients make better, more informed roaming decisions, but to date very few clients have implemented it. Since the clients are currently lacking, it falls to the WLAN system to persuade clients to perform better. Enterprise class WiFi APs gather and share information that can help automatically tune and optimize the environment to provide a better overall user experience.  One of the tools included in the 8.1 release of the Mojo Wireless Manager that can improve overall user experience is Smart Client Load Balancing.

The Closest AP Isn’t Necessarily the Best AP

WiFi clients, if left to their own devices, connect to the closest AP, which can cause problems. Imagine 30 clients close to a single AP, in a classroom or in a meeting room. Most of WiFi devices will connect to the nearest AP, even though there are other APs nearby with good signal strength. There are two inefficiencies that result: 1. Resource Sharing – When 30 clients are on a single AP, the AP’s resources are divided 30 ways, and not always evenly. Overall it would be better if the clients were distributed over the three neighboring APs, even though 20 clients will connect to APs with lower signal strengths. 2. Contention Loss – There is no coordination between devices, so when 31 devices (30 clients and one AP) are transmitting at the same time, there will be collisions. This contention penalty increases and compounds with the number of devices.

Use Case

Smart Client Load Balancing efficiently manages and distributes the clients across APs within the same band can increase the overall capacity of the wireless network.. Background Scanning must be enabled for Smart Client Load Balancing. In high density environments like Auditoriums, Lecture Halls, Public Venues, Conference Centers, Banquet Halls, etc the APs are deployed close to each other to support the large number of devices trying to connect to the network. Since these APs are deployed close to each other, a client device at any given location will be able to see multiple APs with fairly good signal strength. This can end up in a situation where some APs in the network are highly loaded while the others are less loaded. By being able to distribute the clients across APs and across bands within an AP, can increase the overall capacity of the wireless network.

Smart client load balancing distributes the client load between neighboring APs improving the overall operational efficiency. Overall and Individual client throughput increases when the 30 clients are evenly distributed even when the 20 of the clients (10 per AP) connects at a lower data rate (signal strength) because each client get a larger share of its AP’s time and there is much less contention.

Suitable environment

• High density environments like auditoriums, conference rooms, stadiums and lecture halls where AP’s are deployed close to each other and large number of users coming into existence.
• Load balancing could also be useful in a non high dense environment like Enterprises and higher-ed classrooms, K-12 classrooms where bandwidth requirement per client is high.