Answering Service and Paging T1 Applications

By Bill Ranney

In my last article I have discussed how T1 works. This article will illustrate how different businesses have utilized T1 to lower their costs, increase their profit margins and provide better and expanded services to their customers.

TWR Communications (Two Way Radio Service, Inc.), with Jeff Hutter as president, is located in western Maryland. They are an innovator in utilizing new technologies to keep their operating costs low and to provide unmatched service and reliability to their clients. As a paging and mobile telephone company, TWR Communications has equipment housed on remote hill-tops throughout the western part of the state. These unmanned remote equipment sites are the transmission centers through which TWR sends its paging and other broadcasts. Client radios are also housed in these remote site s. In turn, these remote transmitter sites are all linked via radio to a central remote transmitter site, located on a small, in accessible mountain top called Dan’s Rock. TWR’s main office and switch gear is located in Cumberland, about 12 miles from Dan’s Rock.

TWR has two T1 circuits coming into its Cumberland office. One T1 goes to the telco central office and carries all the incoming paging and mobile telephone calls. This digital service gives them crisp digital transmission between their equipment and the central office switch. A new, second T1 goes from the Cumberland office to the top of Dan’s Rock, and carries all of the broadcast traffic. The paging radio, located in Cumberland, can communicate directly with the Dan’s Rock transmitter via a channel bank and this T1 circuit. The T1 also carries data for real time usage, traffic history and configuration. Furthermore, an audio channel piped back from Dan’s Rock via the T1 allows the monitoring of all the transmitter sites throughout the state. No longer does a tech have to run up to Dan’s Rock every time a client gets nervous about their radio transmission; TWR can simply listen to the transmissions at the Cumberland office via the T1 signal to be sure all is well.

And speaking of technicians, TWR has two crack technical people who keep the entire system, along with the computer operations, up and running: Kenny Allman and Toby Preston. Although problems with the T1 and associated equipment are rare, these two are always trying to improve the company’s network, continuing to make it more efficient and more and more reliable.

Kenny and Toby have even designed a back-up UHF link, used to replace the T1 in the event of any transmission circuit failure or when maintenance needs to be performed and they are investigating other wireless networking ideas.

Another application involves an answering service in Houma, Louisiana; Oil Field Communications Services, owned and operated by Harold Carbo. Harold is continually trying to expand the reach of his business while improving service to his clients. He recently expanded his service to a distant city in Louisiana by using a channel bank and a T1 circuit.

Harold had Bell South put 9 DID trunks and 8 loop start trunks (for call out circuits) directly onto an intraLATA T1 at the central office in the remote city he wished to serve. The T1 then transports calls on these 17 channels back to his main office in Houma.

In Houma, Harold uses a channel bank to change the calls from digital T1 format back to an analog format his Axon switch can use. He answers his client calls as if the operators were in the remote city, and the clients can perceive no difference in quality of service. In fact, Harold stated that the quality of the connections has improved on the T1.

Harold doesn’t have the headaches of managing operators in the remote city or the expense of the payroll, either. He also saves on toll charges when he calls the remote city. The loop start trunks allow him to get dial tone directly from the remote central office through the T1, avoiding all long distance toll charges to this area.

He can also use the call-out lines to increase his revenues without increasing his long distance expense The T1 has enough capacity to expand his service to the remote city to any combination of 24 DID or call out channels.

A third application involves an answering service in Michigan. Community Answering Service, owned by Tom Wingo, is founded on top quality service to the client. While his home base is in Michigan, Tom also has built a good client base in the Chicago area, about 120 miles away. He can avoid having operators staffed there by transporting all the incoming DID traffic originating in Chicago to his Michigan office, where the calls are answered. High quality, seamless service is made possible by digital T1 connections.

Tom has a Startel switch in Michigan and uses a point-to-point InterLATA T1 circuit and a channel bank on each end to transport the calls back from Chicago. As compared to the above example of an intraLATA T1, Tom effectively acts as his own telephone company. He has a small office location in Chicago where he uses a channel bank to digitize the incoming DID trunks and puts them on his T1 circuit. At his Michigan office, he has another channel bank to return the calls to an analog format his Startel can use.

He can also make toll free call-outs and marketing calls back to the Chicago area via the T1 circuit. Thus, Tom saves in numerous ways. By not having to pay and manage operators in a far away location, he has better quality control over him.

Another significant advantage arises from having an equipment location in the remote city. Tom’s T1 is reaching full capacity of 24 channels. Instead of getting another T-span, he can compress the voice traffic to give him 48 voice channels on a single T1. By using ADPCM 2:1 voice compression, Tom can achieve double the capacity of his T1 circuit at virtually no degradation in the quality of the voice transmission. Of course he will have to add an additional channel bank at each end, along with the voice compression equipment, but he avoids the monthly re-occurring cost of an additional T1, giving him a relatively quick payback on the compression equipment.

Remember, T1 span pricing is based on mileage, and there are three components to each T1 circuit: 1) a local loop on your HQ end, 2) the long distance or IXC span and 3) the local loop on the far end.

If you want to expand by acquiring an answering service in a distant city and transport the calls back to your main site via T1, draw a circle on a map of the United States that is approximately 500 miles at its furthest point from your office. Generally speaking, IXC T1-spans longer than 500 miles are too expensive for the acquisition to make sense.

This circle gives you an area of more than 750,000 square miles in which to search for an acquisition. The larger the service you want to acquire, the farther away it can be and still support the T1 charge. Smaller services should be closer to your home site.

Once you have acquired that remote service with a remote equipment site, you can draw another 500 mile circle with the center at the new site and piggy back that additional traffic onto your first T1. This leap-frogging method can economically extend your reach around the country.

Local loop charges also can vary greatly. The local loop charge is the cost that your local phone company will charge you to bring the T1 span from your office to the long distance carrier. If you are looking at a service that is quite far from a serving wire center (commonly known as a POP, which is the place where the long distance carrier will pick up the circuit for the long distance span), or if your home service is far from the POP, these local T1 loops can be expensive. Again, they are mileage based and you are usually stuck with the local Bell company to provide this T1.

Carriers are constantly changing their tariffs, also. For an intraLATA T1, depending on the cost, you might want the carrier to put your DID trunks directly onto a T1, or you may prefer a remote equipment site and do it yourself. For an InterLATA (long distance) T1, the local carrier usually will not terminate trunks directly onto a T1 provided by an IXC carrier, but there are exceptions. To my knowledge, no carrier offers compression services, so you must do that yourself. Finally, before renewing a point-to-point T1 contract, shop around with other carriers to be sure you are getting a fair rate.

Bill Ranney is president of Transnet Engineering, Inc. He can be reached in Boulder, CO at 303-413-0665.

[From Connection Magazine, September 1996]

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