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Advanced Digital Signal Processing on Payloads
VToA can transport voice, other audio, data, and video payloads with equal dexterity and reliability. As packets pass through the ATM network in their digital format, there is an opportunity to perform additional processing on the contents of the packets, if desired, to implement various forms of digital signal processing including compression, silence suppression, encryption, and conversion. The ATM market is just beginning to consider some of these as value-added services that could be offered to customers.
Growing Demand for Data and Internet Services
The growing use of the Internet and the demand for more advanced data services has caused major problems in the PSTN. The PSTN was originally designed to handle relatively short duration calls that had certain types of statistical distributions. These numbers were used to calculate how many trunks would be needed to provide service for all the customers in a region. The average call duration for an Internet dialup call or other data call exceeds the design parameters of the original PSTN. The effect of this is that T1 lines that carry the calls are tied up longer, reducing the availability of service to the customers in a region as mandated by law. The only way that phone companies can resolve this issue with TDM technology is to add more T1 lines—an expensive solution.
VToA enables carriers to bypass the PSTN and handle more traffic because the circuits used to carry it are virtual, (i.e., they are defined only by a logical path, virtual channel [VC], through the ATM network). ATM technology provides bandwidth on demand in its packet-switched framework, so each call has its own VC through the network that can be billed based on actual payload transmitted—not a flat rate based on tying up a physical connection. The voice samples are sent using ATM packets, which can be reliably and flexibly routed to their destination without tying up expensive trunk circuits for the entire call.
Lower Cost, Higher Bandwidth Demands from Businesses
Dollar for dollar, VToA delivers nearly twice the capital investment return for carriers as TDM equipment. This allows for network growth that can keep pace with demands from the business community. In most cases, it also enables carriers to add capacity without requiring additional facilities. Some of these savings can be passed on to customers.
