The INS Group has Architected, surveyed, designed, staged and deployed WiFi WVoIP capable networks in over 50 engineering, office, Hi-Rise buildings and campuses in North America. Almost all of these facilities have had projects that also required switch/route/FW, WAN and physical layer upgrades as well. We have upgraded many of these sites multiple times over the years starting with some of the earliest WiFi technologies like 802.11 b FHSS to 802.11a/b/g/n/ac. With a Total WiFi coverage square footage deployed of over 100 million square feet.
The architectures we develop are designed to meet or exceed our customer’s requirements. The architectures are also based on standard protocols and industry best practices. Often times interoperability/design validation testing is necessary when introducing new products into a clients existing network. A WiFi network design must meet the performance, security, segmentation and most of all the user expectations. Proper VLAN/WLAN segmentation that results in the creation of zones tied to specific business functions is critical for security, efficient traffic flows and addressing schemes. This creates a high level of granularity and ease of integration with FW’s, ADC’s (application delivery controllers – loadbalancers) and the switch/routing functions of a well designed network. Which allows for seamless integration into monitoring systems that can easily shutdown a user, SSID, or entire wireless system if necessary. Product maturity and supportability are no less important and we work with our customers to achieve the proper balance of in house and/or service based support.
The INS Group has been performing Wireless surveys for the past eighteen years. We’ve performed surveys in engineering, administration/office, hi-rise buildings and campuses. These surveys were always WVoIP quality or better and some facilities required RFID capable environments as well. Our teams performed active, passive, predictive surveys and often times a mix of these three techniques to come up with the most cost effective solution. Hi rise buildings pose some additional survey challenges to avoid channel contention issues from floor to floor. Prior to performing a survey it’s important to understand what the client expects from their new or upgraded WiFi network. The devices, applications, number/types of users and how will they be using the network is a key part of our requirements gathering. Some key characteristics of the client device types and how they will be used. Which devices have the weakest field strength (power output to AP), these devices will typically be used as the base line when performing an active survey for a new deployment or a passive survey of an existing deployment. This should result in coverage cells that are sized to match the weakest device. It’s also important to test the devices while in motion to verify that signal variability as devices move away from an associated AP will roam successfully before voice quality MOS score falls below 3.5 (or what's deemed acceptable by client) and voice quality is maintained after the roam.
It’s also critical to constrain wireless signals as much as possible from propagating outside the buildings/premises they were designed to operate within. This is an essential physical layer security element that helps guard sensitive information and protect client data networks. RF signals in many situations (offices in cities) will obviously bleed outside the customers premises. In these situations its also important to design around interference from outside sources, whether just passive or a guided threat. This is why encryption and authentication are also important to implement for all wireless networks. So it’s a standard procedure during the survey process to do propagation checks as well as identify outside interference and threats.
Many of the engineering/office projects that The INS Group has deployed not only included the WiFi/WLAN but also the LAN, WAN and network application services. A preferred logical architectural/design for most of these medical environments is to push a high availability OSI layer three architecture out to the access layer. This especially makes sense with today’s modern ASIC based routers or layer 2/3 switches. This is not always practical, which largely depends on the current networks capabilities and whether funding is available to make necessary upgrades. Often times the best strategy is to develop architectures that can move customers toward an optimal financial and technical solution.
Small facilities for example might have a collapsed design where core, distribution and access are on a pair of layer 2/3 switches. This type of physical infrastructure quite easily lends itself to a logical layer 3 solution. Small to medium sized buildings may have combined core/distribution with separate access layers, whereas large buildings and campuses would follow the same architecture but break out into separate core, distribution and access layers. These larger facilities may also have a data center component that would be designed with a separate distribution layer tied to the core. The criticality of these networks demands high availability, fault tolerant architecture/designs with the following guidelines:
1. Core and distribution layers must be highly fault tolerant with redundant electronics and communication links
2. Redundant access layer communication links.
3. Intelligent VLAN segmentation
i. Broadcast isolation/reduction
4. Rapid failure recovery
5. Scalable to meet all network needs
iv. Accommodate proprietary equipment and communications protocols
v. Dynamic load balancing at OSI layers 4-7
6. Multicast capable
7. VoIP/WVoIP capable
8. QoS that is properly buffered and queued to accommodate various application requirements.
i. Deterministic low latency real time traffic is isolated
ii. Guarantee of service
9. Apply proper congestion management and avoidance
10. Eliminate spanning tree loops
11. Layer 1-7 Security controls