Secure Wireless

IT Solutions that Work^SM

Overview

We struggled how to write this section because any discussion of wireless needs to start with a technical overview. But that can be difficult as the concepts can be a bit involved.

At the risk of over simplification, there are two types of architectures for wireless LANS: micro-cell and blanket. Micro Cell is far more prevalent and it involves a wireless device like a laptop associating with Wireless Access Point (AP).

The Typical Access Point (AP)

Before going on to the wireless architectures, let us look at the typical Acces Point. Whether the access point is integrated with a router (not recommended) or a stand alone device does not matter, its functions are the same. It consists of a radio section which transmits signals to and from the end device (the laptop in our example), logic to control the security session, logic to communicated with the upstream LAN infrastructure, and a few other items. The typical AP can only transmit on one radio frequency (channel), the selection of which is set at configuration time.

Micro Cell Infrastructures

The traditional cell-based WLAN topology is architected as multiple cells where no one adjacent cell is broadcasting on the same frequency (channel). As an example, imagine an office with three adjacent APs. When this laptop moves out of range of one AP it must disassociate with it and then re-associate with the next AP that is now closer in range.As it continues to move it again needs to disassociate and then re-associate with the next AP that is now closer in range. In so doing, our example laptop looses a connection when going from one cell to the next, as it needs to change frequency channels. This handoff does not promote seamless mobility or continuity of the security session.

In micro cell design adjacent cells must be on separate frequencies or channels or interface will result.

These issues are not a problem when you a have couple of static endpoints and only one service like data. In many small office environments the problem is not an issue until you channel planning multiple APs, each which need to be on a non-adjacent /non overlapping channel.

The real problem comes to fore when the endpoint devices are mobile. Imagine a mobile medical cart full of devices that are transmitting vital information back and forth or a warehouse automated stock picker that moves throughout a large warehouse. Or put another way the problem is that this approach is fundamentally challenged by its inability to adjust to channelization issues, AP-to-AP handoffs, and the unpredictability of system bandwidth. These problems are multiplied when different traffic types (voice and data) contend for the same airspace.

The end result is trade-offs between coverage, capacity, mobility, and security.

Blanket Wireless LAN Infrastructures

The blanket approach is different. Instead of deploying the traditional AP, only the radios are deployed throughout the facility. These are then managed by a central switch or switches that contain the other AP logic plus logic to allow for seamless wireless mobility without the need associate/disassociate as one moves about. Unlike the deployment of traditional APS where one needs to be concerned about channel overlap and resultant dead spots, the blanket approach permits high density radio deployment where overlap is planned to provide to the highest level of throughput. The central switch controls which radio will provide the best throughput for end devices (our laptop) and seamlessly hands off the connection from one radio to the next as one moves about in the facility.

Another benefit is the blanket vendor we support (see below), radio is capable of transmitting on 4 channels simultaneously. For example, data can be one channel, voice on another, RFID on a 3rd, Video on the 4th. If you need more channels, then simply two radios per deployment spot. I think you can see the benefit of this approach as each channel will not compete for bandwidth and slow down other critical applications (video with not interfere with voice, or data will not interfere with video, etc.)

IT Solutions that Work^SM

Engenius Technologies (MicroCell Architecture)

L4 Networks has tested, deployed and supports the Engenius line of products. The are excellent and secure devices for office environments where mobility of the endpoint device is not a factor. One of their APs is cleverly disguised as a smoke alarm which makes I an appealing deployment in public areas.

Engenius also has outdoor APs that have excellent power and coverage. Typical applications are sports events, fairgrounds, marinas, outdoor cafes, and even small hospitality settings.

All of the Engenius line can be optioned as an affordable secure “Ethernet Bridge” to link two buildings. We have successfully done this for several sites including a health clinic. In this case the savings were great because it avoided jack hammering the parking lot and laying down private fiber.

Extricom (Blanket Architecture)

For the blanket wire less system, we selected Extricom. It has been successfully deployed in numerous industries where seamless mobility is essential. These include hospitals, clinics, elder care, and urgent care facilities, warehousing, schools, manufacturing, retail, and government.

The Extricom wireless LAN (WLAN) product family is purpose-built to deliver robust, reliable connectivity. Extricom innovation makes the All-Wireless Enterprise possible by delivering voice (VoWLAN), data, video, and location services with an always-on, consistent, and mobile Wi-Fi connection to any client, in any environment.
Their WLAN means choice without compromise as it supports multiple and diverse applications all from a single infrastructure at maximum performance. Extricom's deployment simplicity and operational flexibility means the investment you make to achieve today's goals will continue to deliver results throughout the system's life.

Click here for the Extricom product brochure

We just don't talk about IT, we get IT done.^SM