Computer repair san antonio

Utility balances business needs with next-generation communications services.

While other utilities are developing new channels for business, City Public Service of San Antonio, Texas, U.S., views its existing communications infrastructure as a versatile vehicle to improve operations and serve new markets. This vehicle's dri-ver is reliability, which expects to deliver fault-free service, while leveraging the capability to provide future communications offerings.

Replacing the utility's microwave and copper facilities became a necessity as a result of problems with several excessively long copper relaying circuits. Even with highly qualified technicians, City Public Service - the second largest municipally owned utility in the United States - found it difficult to administer and monitor its communications network and minimize outages. A rising demand for Ethernet and high-speed data circuits, and an exploding number of POTS (plain old telephone service) lines to support dial-up applications caused the utility to realize its need for a more versatile service infrastructure. A typical work location required more than 50 POTS lines, the bulk of which had to be provided through leased facilities.

Fiber First The first step in making a sensible network migration was to lay fiber-optic cable between all of the utility's substations, key administrative offices and power plants. To date, the utility has installed more than 400 fiber miles to connect more than 220 nodes in urban and remote areas. Next, City Public Service implemented a SONET (synchronous optical network)-based system that could be managed and configured from a central site and provide the flexibility to support a wide range of communications services. The utility selected the JungleMUX system (see sidebar) from Nortel Networks, not only because of its ability to meet reliability and service objectives, but also because the system is designed specifically for utilities.

The JungleMUX is an in-tegrated SONET add/drop mul- tiplexer capable of operating at optical carrier level 1 (OC-1), equivalent to 51.84 Mbps, and optical carrier level 3 (OC-3), equivalent to 155.52 Mbps. Hardened to meet IEEE/ANSI surge withstand capability (SWC) specifications for surges and transients and IEEE/ANSI radio frequency interference (RFI) standards, JungleMUX's modular design allows each node to be customized for different application requirements, from Ethernet and T1 service to four-wire voice and POTS lines. The utility considered these to be key requirements in terms of tailoring individual sites for current requirements and expanding service as needed.

Implementation and Design Protective-relaying circuits that had experienced the most outages took the highest priority. Service improved immediately and dramatically when the circuits were moved from microwave and copper onto the JungleMUX backbone, demonstrating that the SONET-based solution was secure and reliable. The utility configured the network into four rings that served general business, generation management, energy management and wireless wide area network (WAN):

- For general business, two OC-3 rings configured with Ethernet cards support hubs and routers at various ad-ministration offices.

- For generation management, one OC-3 ring provides connectivity to power plants.

- Fifteen OC-1 rings, slaved off of two OC-3 rings, support the energy management system (EMS), providing protective relaying, supervisory control and data acquisition (SCADA), telephony, and other data applications at the substation (Figs. 1 and 3).

- For the wireless WAN, the ring supports 800-MHz sites for wireless applications in the field, allowing transmission of two-way radio and mobile data via remote site transceivers to dispatch vehicles.

The JungleMUX Network Management system manages the network with JungleMUX Network Craft Interface software. The graphics-based system provides different levels of network monitoring and configuration of nodes. Management down to the DS-0 (Digital Signal) level gives service personnel the visibility and control they need to provide efficient support with the greatest uptime. To further boost management control and reliability, the utility is considering using the system to provide redundant information to multiple control centers. In this way, if one control site goes down, information can be rerouted via the fiber network to a backup center.

Results While the technology has significantly improved operations, the real benefits behind the fiber-based solution are the bottom-line business results. Leveraging the capabilities of the JungleMUX and the high level of reliability of SONET has enabled the utility to provide the best service and support to its internal and external customers, which has dramatically improved business:

- Fewer outages. Especially in terms of protective relaying, the fiber-optic solution has created a highly reliable and survivable service infrastructure. Even when a circuit is lost because the network is configured using self-healing rings (versus a point-to-point topology), the path between nodes is immediately restored without service disruption. Fewer outages translate into more productive internal users, reduced maintenance and repair costs, greater operational efficiencies and more satisfied customers.

- Improved circuit control and tracking. Ethernet connectivity to the utility's major substations provides a wealth of information on equipment performance and faults, allowing personnel to identify issues remotely and solve problems more effectively. Engineers can access fault recorders installed at substations via high-speed data SCADA circuits. These circuits allow them to reset parameters and ga-ther information on the characteristics of the fault at their desks. The utility is considering the same kind of Ethernet connection to monitor dissolved gases in transformers. The connection would enable technicians to identify problems before failure, withthe potential for saving millions of dollars.

A field technician also can connect a personal computer (PC) to the Ether-net port in the substation to upload and download data, which can then be transmitted to a central server site.

- More efficient, effective field dispatch. With increased flow of information at the substation, the trou-bleman is better prepared to handle dispatch requests more speedily. In addition, the wireless WAN increases the troubleman's efficiency by providing mobile voice and data capabilities. The troubleman may receive a dispatch request via the two-way radio directing him to a specific location while, at the same time, his PC provides him with site information, a phone number and a detailed description of the work to be done. The troubleman then notes the completed work in his PC and transmits it to central dispatch for tracking and follow-up, which provides the dispatcher with up-to-date information on the activity.

Applications for the Future As City Public Service continues to extend the capabilities and reach of its network, it has recognized the value of the technical resources available from its vendor. These resources may become helpful in the future when the utility explores new applications to further leverage the network's plat-form with, for example, video connectivity to improve monitoring and security at substations. In addition, the utility will be able to install a master station at a substation or along a right-of-way to provide fiber or wireless connectivity all the way into customers' homes. Such an installation would enable employees to read meters and provide energy management from a central location.

Although San Antonio has not mandated deregulation, its citizens may eventually approve customer choice. If they do, City Public Service is poised to meet the needs of its customers today and in the future and will be in a strong position to compete for business. The utility is confident that its move to fiber-optic and JungleMUX technology has met its objectives for reliability and flexibility and will ensure its success in the future.