by Michael Bouchard and Michael Catizone

A major driving force in the development of broadband is the capability to delivery telephony. Analysts are predicting that shortly after the turn of the century the IP telephony market will exceed $2 billion.

As the world seeks cost effective solutions to meet expanding telecommunications needs, providers of broadband connectivity to MDUs and MTUs are positioned to be major competitors in this marketplace.

The following overview is intended to provide a general understanding of two entirely different telephony concepts that are potentially valuable services provided to tenants through broadband connectivity. Voice over IP (VoIP) versus IP Telephony.

Voice over IP

Voice over IP is the ability to deliver a local dial tone in a market. This means that as a provider you act as the local telephone company. Voice over IP gives the provider the ability to do back hauling, toll bypass and least cost routing of voice and fax calls in a transparent fashion to the end user. The dial tone is delivered over a digital infrastructure at a voice quality equal to or greater than the quality delivered by conventional means.

A key aspect of voice over IP is that it offers the capability to compress a voice circuit and deliver multiple circuits in the same size bandwidth. Typically, a six-to-one ratio can be achieved with minimal impact on voice quality.

IP Telephony

IP Telephony is the ability to run voice, video and data across one common infrastructure. This requires a telephony server deployed on a standards based network. This allows for delivery of IP telephony to any subscriber in the broadband wireless local loop. The typical telephony server is scalable to support up to 50,000 users and is only involved in connecting and disconnecting calls. Its involvement affords it to produce call detail records to be used for billing or other purposes. There are three tiers of IP telephony solutions that vary in quality and cost.

The third tier is the least expensive solution. This uses a software package installed on a computer which allows the user to take advantage of their full duplex sound card to conduct phone conversations through their network connection to other uses on the infrastructure. This would be used for the average home user who conducts few phone calls each month. This a good option because the cost is minimum due to the fact that the only purchase which needs to be made is software.

The second tier is an external phone which connects to the serial port on a computer and provides the same functionality as the third tier, but through a device which resembles a typical telephone handset including a dial pad with redial and mute features. This solution is slightly more expensive, but is more practical for more active users and delivers an enhanced voice quality.

Tier one has two solutions. The first is a device that has a network port and two POTS ports. This device allows for a connection to two standard telephones such as an answering machine, fax machine or phone to the network without requiring a computer. This is typically employed in a home or SOHO environment.

The second tier one solution is a self contained device that resembles a full feature, multiline business phone that does not require a computer and has a built-in network port. Tier one is a top of the line solution that typically delivers the best quality voice with the most amount of features and does not require a computer. This is typically employed in a medium to large office in place of a business phone.

The Gateway

IP telephony can be expanded by the addition of a bidirectional IP telephony gateway. The IP telephony gateway connects traditional telephones to IP telephones. This enables customers of the broadband local loop to place and receive calls anywhere in the world.

In conclusion, providers of broadband can deploy voice over IP and/or IP telephony in stages, which coincides with their business model. The ability to deliver an integrated, IP based voice solution along with data and video services enables the operator to deliver full telecommunications infrastructure to any market in the world.

About the authors

Michael Bouchard is Chief Integration Scientist with Nashua, NH based Third-Rail Integrated Services. He may be reached at michael.bouchard@third-rail.net. Michael Catizone is an integration engineer with Nashua, NH based Third Rail Integrated Services. He may be reached at michael.cartizone@third-rail.net.

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