EIA/TIA-136-750:1999 (R2013)

Purpose and Scope The General UDP Transport Service, GUTS, is a general-purpose application data delivery service. The General UDP Transport Service increases flexibility of adding new value-added features, and creates an open platform for the creation of both consumer and corporate information services via wireless Internet and intranet access. GUTS utilizes the Internet Standard User Datagram Protocol (UDP) to specify the intended application, or port. The General UDP Transport Service provides a new teleservice specially designed to require minimum protocol overhead allowing more room for the data payload (i.e., GUTS is not based on the Short Messaging Service). The General UDP Transport Service supports both mobile-terminated (point-to-point and broadcast), as well as mobile-originated services. The General UDP Transport Service assumes no specific encoding of the application datagrams, and transparently passes the data to the application specified by the destination port. GUTS may also be used to integrate many current TIAEIA-136 features into the common user interface of a browser. For example, GUTS may be used to support one-way and mobile-originated 'Cellular Messaging Teleservice (CMT)'-like messaging and other services associated with the traditional CMT service (e.g., bulk messaging), or 'broadcast' services. In effect, GUTS combined with a browser application can provide a common and consistent user interface for both enhanced and existing TIAEIA-136 services. The General UDP Transport Service can carry essentially any higher layer application protocol. For mobile-terminated services, the messages defined in the General UDP Transport Service carry UDP datagrams from an application in the network (in this architecture, the Application Server or Gateway), to the appropriate application in the mobile station (for example, an HDML Browser). Similarly, for mobile-originated services, the messages defined in the General UDP Transport Service carry UDP datagrams from an application in the mobile station (for example, the HDML Browser), to an application in the network (the Application Server or Gateway). These applications are defined by appropriate UDP ports. Port assignments are necessary for the UDP portion of the protocol. These port assignments may be outside of the UDP Well-Known port assignments, as it can be envisioned that existing applications defined in the Well-Known port assignments may be used in the General UDP Transport Service. The port assignments inform the receiving end of the UDP datagram which application the data should be delivered to. On a mobile-terminated GUTS Data message, the mobile station delivers the datagram to the GUTS application. The Destination Port specifies the particular application within GUTS for which the UDP Data should be delivered. For example, if the Destination Port specifies the port for the HDML/WAP Browser, then the GUTS shall deliver the data to the HDML/WAP Browser, as shown below: