Ekahau

Jul 20, 2022

Wireless access in healthcare is high stakes and requires high availability. A properly designed IEEE 802.11-compliant wireless network can support continuous patient telemetry and VoIP in an enterprise healthcare environment. by Terry Pelkey is a professional wireless engineer with 22 years of experience in IT. He spent the past six years specializing in enterprise healthcare wireless. Pelkey recently implemented this methodology when remodeling the emergency department at a hospital that sees over 78,000 emergency visits annually. He holds the following active certifications: CWNP Certifications: CWNA, CWSP, CWAP, CWDP, CWISA, CWIDP | Ekahau ECSE | Cisco Certifications: CCNA Wireless, CCNA Collaboration, CCNA R&S, Cisco CCENT. Listen   Healthcare systems require a consistent, reliable and strong wireless connection to support real-time patient care and monitoring. Connectivity is required in all locations accessed by patients, including bathrooms and showers. The multitude of factors and variation in structural composition across these locations present significant challenges for wireless engineers providing this service. It’s important for wireless engineers to understand best practices for the design, deployment and validation of wireless services that are compliant with the IEEE 802.11 Standard for Wireless Networks and that support constant, real-time patient telemetry and Voice over IP in an enterprise healthcare environment. A U.S. hospital recently achieved the successful implementation of a Philips telemetry running over 802.11 on the 5 gigahertz band. The hospital has since been held up as a gold standard benchmark by Philips to show that it is possible to use real-time patient telemetry over 802.11 when the proper design protocols are followed and the WLAN is properly tuned. Wireless engineers looking to design a similar system should carry out the following instructions, which are intended for new wireless network constructions, but also can be adopted to wireless network upgrades. 1. Create an Accurate Predictive Model for Wireless Networks The predictive model is the starting point for designing a wireless network that supports healthcare system requirements for constant availability of wireless devices. A software application such as Ekahau Pro can help engineers design a wireless network. However, automated artificial intelligence modeling software alone is not sufficient for accurate radio frequency (RF) designs. Understanding the floor plan, building materials, access routes and equipment that will be connected to the wireless is crucial for building an accurate predictive model. Wireless engineers should start with the most up-to-date CAD drawings for the facilities where real-time patient monitoring is requested. Ideally, the wireless engineer tasked with the design will visit the site at different stages of the construction project. This allows the engineer to understand the types of materials used for the walls, ceiling and floors, as well as the materials that will be built into the facility, such as stainless steel, lead, electrical components, tube systems, plumbing, etc. These materials introduce multipath, reflection, refraction and absorption of the RF signal into the design considerations. These components should be factored into the design of the wireless implementation for the model to be predictively accurate. The more detail incorporated into the predictive model at the beginning, the more closely the validation survey will align with the model. 2. Be Ready to Suit Up When Surveying the Healthcare Site Surveying a construction site typically requires attending a safety class and wearing personal protective equipment (PPE) before entering the site. Alternatively, visiting an emergency department or ICU wing may require surveying outside of standard hours to avoid interfering with surgery schedules or other critical operations, in addition to wearing PPE. During site visits, take pictures, videos and notes of the various construction stage, which will assist in adding details into the predictive model. Incorporating the knowledge of building materials, floor plans and details from photographs will result in a truly predictive model that closely aligns with all requirements when implemented. A well-designed, thorough and accurate predictive model will help reduce issues during implementation, meet business objectives in a timely manner and save the healthcare system costs in IT resources. 3. Understand the Health IT Devices Supported by the Network The types of devices and applications that must be supported on the wireless network have an impact on the network design. It’s important to understand a device’s security capabilities, such as WPA2-PSK or WPA2-Enterprise. Typically, EAP-TLS or EAP-PEAP is used for the wireless LANs such as Vocera devices, VoIP phones, smartphones and tablets. During the predictive modeling stages, build in the requirements using the least capable, most important device (LCMID) methodology. This is a significant challenge in healthcare environments because there are a multitude of devices constantly connecting to the wireless networks. Use LCMID methodology to focus on the critical devices and models that must connect to the network, such as patient telemetry using real-time applications, VoIP devices such as Cisco or Vocera, and mobile devices using applications such as Voalte or Mobile Heartbeat . Once these are identified, shift the focus to the vendor requirements to support these devices. Be aware of these requirements during the modeling stages: The version of wireless support, such as 802.11b/g/n/ac/ax Channel width support: 20-40 megahertz Multiple-Input Multiple-Output support for the number of spatial streams 1/2/3/4 Maximum supported transmit power Roaming threshold If documentation with this information is not available, the Federal Communications Commission identifier listed on the device is an excellent resource for learning what the device can support. The FCC ID Search and Redirection tool uses the FCC ID to return this information to aid in the design of the predictive model. LCMID vendor requirements that include newer devices capable of supporting multiple spatial streams with 802.11ac/ax are less likely to experience performance problems when connected to the WLAN or when using applications for electronic medical records, web browsers, word processors, VoIP and roaming. 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 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. 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 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