WLAN Design: Range, Performance, and Roaming Considerations
This chapter will introduce you to:
- Range Versus Performance
- Range Considerations
- Performance Considerations
- Roaming Considerations
When designing a wireless LAN (WLAN), take care to ensure that the WLAN will satisfy requirements for signal coverage, performance, and roaming. Problems related to these items often crop up when supporting a WLAN, generally due to designers not considering all relevant elements of the design. This chapter provides insight and addresses important elements you should consider to avoid these problems.
Range Versus Performance
It would be great if WLANs had unlimited range and performance. If this were true, the job of designing a WLAN would be much easier. There would be no need to consider the multitude of design elements to ensure that there was enough signal coverage and capacity for supporting your applications. Unfortunately, due to the constraints of physics, definite range and performance limits apply.
In addition, something that complicates the design is that range and performance are sometimes indirectly proportional. By increasing some design elements (for example, transmit frequency or data rate), the performance will increase but range will decrease (if all other design parameters, environment, and so on are constant). In other cases, changing design elements, such as transmit power and antenna gain, will increase performance and range. As a result, you must be familiar with how changing various design elements impacts range and performance to design an effective WLAN.
In addition, ensure that you have a solid understanding or the WLAN requirements dealing with performance, signal coverage, and the operating environment before getting started with the design. You will need to know this to determine which elements are most important and worthwhile to change.