A WLAN uses radio signals (high-frequency electromagnetic waves) to transmit data. The strength of radio signals becomes weaker as the transmission distance increases. In addition, adjacent radio signals cause interference overlapping. All these factors reduce the signal quality or even cause network unavailability. To improve the WLAN quality and meet customers’ requirements on network construction, WLAN planning and design are required. During the WLAN planning, the AP (AirEngine 5760-51) models and quantity, installation positions and modes, and cable deployment modes need to be planned to ensure pervasive wireless network coverage, fast Internet access, and optimal network experience. If WLAN planning and design are not performed in the early stage, rework may be required after APs are installed. This is because network optimization after APs are installed may require AP reinstallation and re-cabling.
WLAN planning is performed to address the following issues:
- Weak signal strength: If the actual transmit power of APs is not considered during the wireless network coverage design, coverage holes may exist. In this case, the signal strength is weak or even no signal is available. As a result, users suffer from slow Internet access or even cannot access the Internet. Therefore, the coverage area of each AP needs to be properly planned during WLAN planning to ensure that each area is covered by strong wireless signals.
- Severe co-channel interference: Co-channel interference is generated when radios of two neighboring APs work on the same channel. When co-channel interference occurs, signals of the APs are interfered and delays arise when the APs receive and send data simultaneously, which greatly reduces network performance. Therefore, different working channels that do not interfere with each other need to be allocated for APs with overlapping coverage areas.
- Slow Internet access: WLANs use the Carrier Sense Multiple Access with Collision Avoid (CSMA/CA) mechanism. The probability of wireless packet collisions grows as the number of concurrent access users increases, thereby slowing down the Internet access speed. For example, in high-density scenarios such as stadium stands, a large number of wireless users connect to each radio of APs, causing a high probability of wireless packet collisions. In these scenarios, three-radio APs with high-density small-angle directional antennas are recommended to control the number of access users on each radio and reduce the packet collision probability.
- No obvious advantage in user experience in VIP areas: VIP areas require special attention during WLAN planning. The Internet access experience of users in VIP areas should be preferentially guaranteed.
You need to design a WLAN planning solution based on customer requirements. If you cannot obtain complete and valid information in the requirements collection phase, the subsequent WLAN planning may not go smoothly or even needs to be re-designed. We list the important information that needs to be collected for WLAN planning, helping you collect accurate and effective information in a targeted manner.
|Laws and regulations||Determine the country code to be used according to the laws and regulations of the region where the network is located.|
|Onsite construction drawings||Drawings are used to design the WLAN planning solution. Obtain complete drawings that contain the scale information from the customer. CAD drawings are recommended. PDF, PNG, or JPG images can also be used.
If no drawing is available, measure the actual data on site and draw drawings with the scale information.
|Wireless network coverage area||Confirm with the customer VIP areas, common areas, and simple areas.
· VIP areas: network coverage areas for VIP users, requiring high network quality
· Common areas: main network coverage areas, such as office areas, classrooms, dormitories, and hotel rooms
· Simple areas: areas with only a few network usage requirements, such as corridors, storage rooms, and kitchens
|Field strength of wireless signals||Check whether the customer has requirements on the signal strength in the coverage areas. Typically, the signal strength in VIP areas is greater than –60 dBm, that in common areas is greater than –65 dBm, and that in simple areas is greater than –70 dBm.|
|Number of access users||Calculate the total number of access terminals in the current coverage areas. For example, in a wireless office scenario, if each user has a mobile phone and a laptop, the number of access terminals is twice the number of access users.|
|Terminal type||· Confirm the terminal type and quantity. Common terminals include mobile phones, tablets, and laptops, while special terminals include barcode scanners and cash registers.
· Determine the proportion of each MIMO type of these terminals to estimate AP performance. This depends on the customer’s technical capability. Collect this information if available. If the customer cannot provide this information, use 2×2 MIMO to estimate AP performance.
|Bandwidth requirement||Determine the main service types carried on the network and bandwidth requirements of each user.|
|Coverage mode||Check whether the customer requires indoor settled, agile distributed, or outdoor APs for coverage.|
|Power supply mode||Confirm with the customer the required power supply mode and available onsite power supply areas and facilities.|
|Switch location||Determine the positions of wired-side switches upstream from WLAN devices. Check whether the PoE power supply distance meets the requirements.|