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Telecommunications
Published in Jay Liebowitz, The Handbook of Applied Expert Systems, 2019
There are many existing automated network management systems containing AI modules for diagnosis, repair, and service dispatching. AT&T’s ACE maintenance expert system was developed in the early 1980s (Liebowitz, 1988). Today, ACE has been sold and installed in more than 100 sites. ACE is a rule-based system that assists telephone engineers in maintaining the local loop. The local loop is the part of the telephone network that connects residential or business telephones with a local switching center. ACE is a background data analyzer that does its analysis by querying the database of daily test results stored in the Cable Repair Administration System (CRAS) and looks for patterns in the data that indicate where trouble may exist in the local loop. Each output of ACE is a classification or diagnosis of the problem, along with detailed support evidence from the CRAS system. ACE uses a forward-chaining rules strategy that breaks the overall problem into independent subproblems. Each subproblem can therefore be solved independently and the results assembled into a complete solution.
Wireless networking
Published in Matthew N. O. Sadiku, Optical and Wireless Communications, 2018
The wireless local loop (WLL), also known as fixed-wireless services, is now being used in place of conventional wire-line connections between the local exchange and customer premises. Conventionally, the local loop or access network consists of a pair of copper wires, buried or suspended in air, connecting subscribers at home or office to the nearest telephone exchange. It is typically 6 to 8 km long, and the copper gauge used is 0.5 to 0.6 mm. Local loop is designed to carry 4 kHz voice and is difficult to maintain, with 85% of all faults found in the local loop. It is expensive and time-consuming to deploy in view of the rising cost of copper and digging.2
American and Japanese Telecommunications Organizations Look to the 1990s and Beyond
Published in Dr. Dimitris, N. Chorafas, Heinrich Steinmann, Intelligent Networks, 2019
Dr. Dimitris, N. Chorafas, Heinrich Steinmann
A recent article in Business Week (July 31,1989) has this to say on the future of the twisted-pair local loop in view of user requirements: “Once United’s local phone companies are outfitted with the same high-performance fiber-optic lines used by Sprint, the slow-growth local business can be transformed into a purveyor of everything from voice communications to information services and cable TV — theoretically with double-digit annual growth.” And they will do so by siphoning business out of those regressive telcos that stay with twisted pair.
A Survey on Packet Switching Networks
Published in IETE Journal of Research, 2022
As mentioned above in figure 1, the local loop is the distance (connection) from the home or company office to the ISP, and the maximum distance is 5 km. The WAN access technologies can be wired or wireless connections, see figure 3. If the user is a home or a small office, the wired connection can be dial-up, DSL, Cable-TV, fiber optic, see figure 4, and the wireless connection can be GSM, WiMAX, Satellite, see figure 5. While if the user is a company/business, then the wired connection can be DSL, fiber optic, dedicated leased lines, Metro Ethernet, and the wireless connections can be WiMAX, satellite, point to point beam, and microwave.