Microwave Wireless Solutions

In today's growing business environment globally the communication of information over distances in a quick manner is becoming essential to stay in the business environment. The purpose of this paper is to give a technical explanation and cost analysis/comparison of microwave unlicensed/licensed wireless as a WAN or as a worldwide networking solution. Microwave in itself is not a new technology; MCI based its beta network on this technology when it was founded in 1968. The difference between the technology that MCI used and what is available today are Bandwidth, FCC regulation, and a list of other "new features". Microwave has developed over the years into a widely-adaptable wireless solution. Including cost-effectiveness, microwave is feasible to implement in many different scenarios making it a possible to implement in many scenarios.

We've put together a comparison to show the cost-differential and bandwidth constraints of wired (T-1) versus microwave (Wireless) Solutions. In that, comparing a wired network to a wireless solution, you can see the benefits of this technology.

Case Scenario

A school district consisting of 4 schools and an administrative building, all buildings are wired with CAT5e supporting up to copper gigabit Ethernet. The LAN is at 100Mbps, the rollout of 1000Mbps is scheduled for 5 years from June of this year. The current WAN setup is slow; A Mesh T-1 Leased Line VPN supplied by Ameritech. Supporting 1.544Mbps, this is barely enough to support the current communication needs between buildings. After evaluating pricing and other needs a consultant is called in to make suggestions concerning which technology should be used to bring the WAN up to speed with the LAN.

The district as a whole is growing at exponential numbers. New students are added to the role call each day. Some of future plans of the technology division are to support Distance learning and On Demand Video, also to support new computer laboratories. These programs require high-bandwidth backbones, which the current T-1 WAN cannot supply.

After meeting with a consultant the board of directors has been given the following options.

* Lease SONET lines instead of T-1s. Therefore increasing the bandwidth to gigabit scales. The downside is cost as the district as a whole cannot afford to lease the lines.

* Install a Private SONET network. Therefore increasing the bandwidth to gigabit scales. The downside is cost once again; despite a 10 year payback the equipment required to support such a network is very expensive. Also, the fiber would have to be buried. The cost of burying fiber throughout the district is not practical.

* Install a wireless solution. The bandwidth constraints vary by vendor and product, but 100-255Mbps is easily supported by most. The downsides are 'line-of-sight' and building code restrictions only allow certain towers to be used. Also, the variations between unlicensed/licensed technologies can lead to FCC conflict rendering you hardware restricted or useless if the FCC deems your frequency private or recalls it. Wireless solutions include:

o 802.11A/B/G products supplied by Cisco and Stratex Networks

o Microwave products supplied by TeraBeam and Stratex Network

The consultant is now asked to investigate the above alternatives and investigate which technology will best suit the district's budget and requirements.

After weeks of investigations the consultant returns and presents his findings. SONET solutions have been ruled out due to the cost of leasing lines and/or the supporting the lines, which are either leased or buried. Thus, leaving the district with the decision of which wireless solution they must choose to pursue. The consultant is then asked to go out and gather information and present an in-depth presentation on possible wireless solutions to the district in one week.

End of Case Scenario

Wireless solutions in general vary by standard and bandwidth. 802.11A/B/G products cannot support the CBR that is required over the distance that exists between buildings. Also, security concerns involved in 802.11 products force encryption and possibly even MAC Address filtering be placed upon the signal to avoid data theft. The aforementioned factors rule out all 802.11 products. The next step is to investigate the microwave product line.

Microwave in itself is a line-of-sight technology and operates at very high frequencies (7-35 GHz) thus eliminating the security risks of 802.11 products. In order to tap into a microwave signal you must physically be in the line of the signal and capture the data crossing the line, not to mention you need a receiver capable of capturing data from such a high frequency. Microwave solutions support a wide variety of bandwidth and CBRs based upon vendor and product type. The standard ratio is in most part the higher the frequency the more scalable the bandwidth is overall. One variation that has arisen over the past years of microwave product development is the signal licensing. There are 2 variations to this aspect; a signal can either be licensed or unlicensed. Licensed being regulated and managed by the FCC or unlicensed being a distinct range of frequency unregulated by the FCC. Licensed equipment is usually cheaper because it uses an already regulated frequency. Unlicensed equipment is often proprietary leaving the consumer to make up for the cost of developing proprietary equipment, thus a higher expense. The cost of licensed equipment may be less from most vendors but the complications of having to lease a frequency from the FCC are risky at the least. If a frequency, say 26 GHz, is leased for $1000 a year; pending renewal on June 31st of the following year after expiration of the current lease, which is granted to another company which is utilized by a new bleeding edge technology the day after you sign the lease rendering your microwave network useless is you're to deal. If the FCC gives your frequency to another company then you have no choice but to modify your licensed equipment to use a new frequency or buy new hardware that uses another frequency. Licensed microwave is risky, not to mention the added lease renewal costs each year, which can add up to $1000-3500 per year.

Unlicensed microwave equipment utilizes an unregulated frequency range that the FCC has deemed public. Therefore a vendor must develop equipment that uses that open frequency range. The cost of developing such equipment is not cheap, hence the usual higher cost of unlicensed equipment. Certain vendors have reduced