7 Steps to Design an Effective Wireless Network in
For example, a wireless predictive model designed for Philips Telemetry included Vocera B3000n badges for doctors and VoIP communications for nurses. In this case, the Vocera WLAN requirements and Vocera Best Practices documentation were used for this model because Vocera devices had greater WLAN coverage requirements:
- Primary Signal Strength: -65
- Secondary Signal Strength: -67
- Signal-to-Noise Ratio: 25
- Data Rate: 12
- Channel Interference: 1 at minimum Signal Strength of -85
- TX Power: Max 16 dBm (40 mW) – Min 13 dBm (20 mW)
This Philips Telemetry model was designed only for 5GHz. Unnecessary 2.4GHz radios were disabled during the design and staging of the access points. Alternatively, the wireless engineer can place disabled radios into monitor mode to optimize location tracking and security. One of the most critical steps when designing a wireless network in the healthcare environment is using 20MHz channel width. The importance of implementing a 20MHz channel width rather than 40MHz or 80MHz channel bonding cannot be stressed enough. Utilizing a 20MHz channel width in high density deployments allows the reuse of channels to minimize co-channel interference.
A valuable predictive model design incorporates the use of 20MHz channel width and looks to achieve a high-performing 5GHz wireless network that will work reliably for the customer for the next three to five years. Soon, this requirement will shift to 6GHz. To accomplish this, there must be the ability to reuse as many channels as possible. This decreases co-channel interference in a high-density deployment. Vocera provides detailed documentation of the requirements for a successful, high-performing wireless network.
DISCOVER: How Cisco’s OpenRoaming rollout enables quick, secure Wi-Fi access at Adventist Health.
4. Prepare to Deploy a Predictive Model for Wireless Networks
Prior to starting a predictive model, set three or four Vocera badges connected to a WLAN next to each other. Next, open the badge settings to view the Received Signal Strength Indicator (RSSI) reported by each badge. Then, connect an Ekauhau Sidekick device to the Ekahau Pro spectrum analyzer software to view the measured RSSI for that area. Finally, determine the difference between the highest RSSI and the lowest RSSI measured by the badges and the Sidekick device. This difference is the offset for the wireless design.
For example, say the badges have the following RSSIs:
- Badge 1: -70 dB
- Badge 2: -72 dB
- Badge 3: -75 dB
- Badge 4: -68 dB
- Sidekick device viewing as measured: -65 dB
The difference of the highest measured RSSI and the lowest measured RSSI results in an offset value of -10 dB. Therefore, with a built-in offset, the primary coverage is -55 dB and the secondary coverage is -57 dB. Ekahau Pro modeling software is now able to compute this with reliable accuracy using the “View as Mobile Device” feature.
5. Create a Wireless Network Installation Guide
Once the predictive model design is complete, a list of the hardware required to implement the design should be developed. Generating a comprehensive guide listing the type of access points, external antennas and other components used assists with creating the bill of materials and an instruction guide for the installation vendor. All access points, external antennas and other necessary hardware should be included in the bill of materials and the installation guide. The guide documents the following information at minimum:
- Access point model
- Antenna type
The guide provides clear instructions for the installation and placement of each access point and antenna.
It is also beneficial to document the access point name, physical location, MAC address and radio MAC address (for Vocera purposes) to enter the Vocera Administration server or Cisco Prime Infrastructure/DNA Center in the proper location on the maps.
EXPLORE: 4 key advantages of SD-WAN technology for healthcare.
6. Prepare for Wireless Network Installation
Prior to installation, prepare the access points for deployment by connecting Power over Ethernet (PoE) to the access points and registering them to the proper wireless controller. On the wireless controller, create new (if needed) RF profiles for both the 2.4GHz and 5GHz radios along with an AP group. Add the access points to the AP group at this time. Radio resource management (RRM) settings allow wireless engineers to be very specific with radio configurations. It is best not to leave the default settings in place. Customizing the settings allows the engineer to optimize the performance and reliability of the wireless network.
In the aforementioned Philips Telemetry model, the channel plan used for the wireless design turned off unnecessary 2.4GHz radios or put them into monitor mode. Changes to the design were made to accommodate the floor, building or location, and to support the type of client devices in use.
7. Install the Wireless Network Hardware
It is recommended that the engineer conduct onsite visits during the deployment process to verify the proper installation and the associated locations of the access points. Access points should not be hanging from a ceiling tile in a way that points the RF in an incorrect or inefficient direction. Care should be taken to correctly mount access points in an aesthetically pleasing manner, especially in public spaces and new buildings.
Once the access points have been installed and the locations verified, they can be powered on. After they have been powered on, allow the access points to run for at least 24 hours. This allows RRM to make changes to the power and channel settings and other configurations.