Technique for screening work requests

An entity (18) that maintains facilities, such as buried conveyances (12) screens requests by contractors to undertake work that may potentially impact such facilities by comparing the Global Satellite Positioning (GPS) coordinates associated with the location of the work to the GPS coordinates of each facility. In the event that the work will occur within a minimum separation distance from the facility, then the entity maintaining the facility will dispatch a technician to physically locate and mark the facility.

TECHNICAL FIELD 
 This invention relates to a technique for enabling an entity to screen a 
 request for work to determine whether work will occur at a site is 
 sufficiently close in proximity to the location of one of the entity's 
 facilities such that the work may damage the facility. 
 BACKGROUND ART 
 Most utilities, such as those that provide electric, water, gas or 
 telephone service, bury their conveyances (i.e., pipes and cables) 
 underground both for reasons of safety and esthetics. For example, AT&T as
 a provider of telecommunications services, maintains a network of some 
 50,000 miles of buried optical fiber cable installed in a variety of 
 environments. AT&T's network of buried optical fiber runs under city 
 streets, rural farmland, and along other public and private rights of way.
 Although burial does protect such optical fiber cables from the elements, 
 such buried cables, as well as other underground conveyances, do remain 
 vulnerable to damage from excavation by contractors. 
 In many areas, governmental regulations require that contractors seeking to
 excavate first contact a central agency, often referred to as a "One-Call 
 Center," prior to undertaking excavation. Personnel at the center forward 
 such contractor work requests to those entities that maintain buried 
 cables within the region served by the center. Each entity screens the 
 work request to determine whether the work anticipated by the contractor 
 will actually occur sufficiently close to that entity's underground 
 conveyances to require dispatching personnel to physically locate and mark
 such buried conveyances. Each year, One-Call Centers in the United States 
 process numerous requests, so an entity that maintains buried conveyances 
 must devote significant personnel and resources to perform the location 
 and marking of buried conveyances. 
 Some One-Call Centers do a better job of screening work requests than 
 others. For example, some centers will report work requests with out 
 regard to boundaries, while others will screen works requests within 
 boundaries, thus avoiding sending such requests to entities that lack 
 buried conveyances within the specified boundary. However, even screening 
 of work requests based on a specified boundary has its limits. Often the 
 boundary specified in the work request may lack sufficient accuracy for an
 entity that maintains buried conveyances to rely on a general comparison 
 between the specified boundary data and the entity's own conveyance 
 location records for screening purposes. For this reason, most entities 
 that maintain buried conveyances, such as AT&T, often take a "better safe 
 than sorry" attitude and usually dispatch technicians to mark and locate, 
 even though making and locating may not have been necessary. 
 Thus, there is a need for a technique for more accurately screening work 
 requests. 
 BRIEF SUMMARY OF THE INVENTION 
 Briefly, the present invention provides a method for use by an entity, such
 as a utility or the like, that maintains facilities, such as buried 
 conveyances, to screen work requests such as from contractors seeking to 
 perform work in close proximity to a facility to determine whether the 
 work may cause damage to such facility. In accordance with the invention, 
 the entity first receives a work request that identifies the site at which
 the work will occur. Thereafter, the entity receiving the work request 
 establishes the Global Positioning Satellite (GPS) coordinates 
 corresponding to site where the work will occur. In some instances, the 
 work request will include the GPS coordinates of the work site so the 
 entity receiving the work request need only read the GPS coordinates from 
 the request. For example, a contractor may make the work request with the 
 aid of a special wireless telephone that includes an integral GPS receiver
 that automatically provides the GPS coordinates to the screening entity. 
 When the GPS coordinates are not present in the work request, the entity 
 will establish the GPS coordinates, either from a map, or a database that 
 such coordinates for different locations. Once the GPS coordinates 
 corresponding to the work site are established, then the GPS work site 
 coordinates are compared to the GPS coordinates of each facility to 
 determine whether the work site is sufficiently close to a facility to 
 warrant concern.

DETAILED DESCRIPTION 
 Referring to FIG. 1, a contractor seeking to perform work (e.g., 
 excavation) at a work site 10 that may encompass one or more buried 
 conveyances 12 (only one of which is shown) generally must first submit a 
 work request 14 to a One-Call Center 16. The One-Call center 16 screens 
 each work request 14 to determine whether to notify the various utilities 
 18 (only one shown) who may maintain buried conveyances, such as buried 
 conveyance 12, in the region 10 where work is to occur. 
 Each work request 14 contains location information 20 specifying site where
 the where the work will occur. Traditionally, the One-Call Center 16 
 examined the location information 20 to determine whether a utility, such 
 as utility 18, had one or more buried conveyances within the boundary of 
 the work site whose location is specified by the location information 20. 
 If the One-Call Center 16 determined from its records that the utility 18 
 had a conveyance, such as conveyance 12, within the boundary of the work 
 site, the One-Call center passed the work request 14 to the utility. In 
 response, the utility would dispatch personnel to the work site to 
 physically locate and mark the conveyance 12 depending on the utility's 
 policy required separation distance between the conveyance and the work 
 site boundary. 
 Unfortunately, not all One-Call Centers provide good location-boundary 
 screening of the type described above. Some centers simply pass all work 
 requests directly to each utility, forcing the each utility to perform its
 own screening. Such screening is time consuming, and increases operating 
 costs. 
 In accordance with the invention, a utility, such as utility 18, can 
 achieve more accurate screening of work requests by comparing the 
 corresponding Global Positioning Satellite (GPS) coordinates for the work 
 site against the GPS coordinates of the buried conveyances maintained by 
 the utility. To accomplish such screening, the utility 18 maintains at 
 least one processor 22, in the form of a personal computer or the like 
 into which the data contained in each work request 14 is entered following
 receipt of the work request from the One-Call Center 16. For each received
 work request 14, the processor 22 establishes the GPS coordinates of the 
 site where the work will occur. In some instances, the work request 14 
 will include a data block 24 containing the work site GPS coordinates, in 
 which case, the processor simply establishes the GPS work site coordinates
 from the data block 24 on the work request 14. However, the work request 
 14 may not include the GPS coordinates of the work site location. In other
 words, the data block 24 may be devoid of any data. Under such 
 circumstances, the processor 22 queries a database 26 that maps locations 
 to a corresponding set of GPS coordinates. In this way, the processor 22 
 can establish the GPS coordinates for a work site though the associated 
 work request contains no such coordinates. 
 In addition to the database 26, the processor 22 also has access to a 
 database 28 that stores the GPS coordinates for the buried conveyances 
 maintained by the utility. A technique for capturing the GPS coordinates 
 during installation of a buried conveyance, such as an optical fiber, is 
 described and claimed in U.S. patent application Ser. No. 09/089,827, 
 filed on Jun. 3, 1998, in the name of Hossein Eslambolchi and John S. 
 Huffman, and assigned to AT&T (incorporated by reference herein). The GPS 
 location coordinates captured in accordance with the teachings of the '827
 application can be supplied to the database 28 in a variety of ways, such 
 as by direct electronic transfer of data, or via a magnetic or optical 
 medium. By querying the database 28, the processor 22 can compare the GPS 
 coordinates of each of its buried conveyances, such as conveyance 12, to 
 the GPS coordinates established for the work site and determine whether 
 the work site is within a minimum distance as to require dispatching 
 technicians to physically locate and mark the conveyance. 
 FIG. 2 depicts in flow chart form the steps executed by the processor 22 of
 FIG. 1 to screen each work request 14 of FIG. 1. Initially, the processor 
 22 receives the work request 14 (step 100) and thereafter establishes the 
 GPS coordinates for the work site (step 110). As described above, the 
 processor 22 establishes the GPS work site coordinates simply reading them
 from the work request 14 if the coordinates are present in the data block 
 24 of FIG. 1. Otherwise, the processor 22 must query the database 26 to 
 map the work site location to a corresponding set of GPS coordinates. 
 After the processor 22 establishes the GPS coordinates for the work site, 
 then the processor obtains the GPS coordinates for each buried conveyance,
 such as conveyance 12 by querying the database 28 (step 120). Typically, 
 the database 28 contains the GPS coordinates of buried conveyances 
 maintained by the utility 18. However, to the extent that work requests 
 could impact facilities of the utility 18 other than buried conveyances, 
 the utility would store the GPS coordinates of such facilities in the 
 database 28. 
 Once the processor 22 has obtained the GPS coordinates for its facilities, 
 then the processor makes a comparison between the GPS work site 
 coordinates and the GPS facility coordinates (step 130) to determine 
 whether any facility, such as buried conveyance 12, lies within a minimum 
 distance from the work site. If a facility lies within the minimum 
 distance, then a technician is dispatched to physically locate and mark 
 the conveyance (step 140). Typically, such locating is accomplished by 
 electromagnetic signaling. If no facility lies within the work site, then 
 the processor so advises the One-call center 16. 
 FIG. 3 shows an alternate preferred embodiment 100 of the apparatus for 
 screening work requests in accordance with the invention. The apparatus 
 100 of FIG. 3 includes many of the same elements as the apparatus of FIG. 
 1 and like reference numbers are used to describe like elements. The 
 apparatus of FIG. 3 includes a combined wireless telephone/GPS receiver 
 110 for use by a contractor in making the work request 14 to the one-call 
 center 16. The combined wireless telephone/GPS receiver 110 includes a GPS
 receiver portion 112 that operates to receive GPS satellite information to
 establish the GPS coordinates of its location similar to-a conventional 
 GPS receiver. The GPS receiver portion 112 provides the GPS location 
 information to a wireless transceiver portion 114 for broadcast thereby to
 a wireless network 116 which carries the call made by the combined 
 wireless telephone/GPS receiver 110 to the one call center 16. 
 The advantage achieved by having a contractor utilize the combined wireless
 telephone/GPS receiver 110 to communicate the work request 14 to the 
 one-call center 16 is that the combined wireless telephone/GPS receiver 
 automatically provides the GPS coordinates 24. Otherwise, the contractor 
 would need to make the measurement separately, or simply omit this 
 information, requiring that the utility 18 establish the coordinates in 
 the manner described with respect to FIG. 1. Having the contractor use the
 combined wireless telephone/GPS receiver 110 to communicate the work 
 request 14, and thus automatically provide the GPS coordinates 24 will 
 greatly simply improve the accuracy of the screening process. 
 The foregoing describes a technique for screening work requests by 
 comparing the GPS coordinates of the work site to the GPS coordinate of 
 each of a set of facilities to determine if any facility lies within a 
 minimum distance from the work site to warrant physical location and 
 marking of the facility 
 The above-described embodiments merely illustrate the principles of the 
 invention. Those skilled in the art may make various modifications and 
 changes that will embody the principles of the invention and fall within 
 the spirit and scope thereof.