1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 8 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU).4%27/2+).G0G0“%47%.G0G0.%47/2+3%.%2!,%.%2!,G0G0!22!.%-%.43G0G0(b) that Recommendation X.301 defines the general arrangements for call control within a subnetwork andbetween subnetworks for the provision of
2、data transmission services;(c) that Recommendation X.302 defines the general arrangements for internal network utilities within asubnetwork and between subnetworks for the provision of data transmission services;(d) that Recommendation X.75 already specifies detailed procedures applicable to call co
3、ntrol between twopublic networks providing data transmission services;(e) that Recommendation X.10 describes categories of access to PSPDNs for the provision of datatransmission services;(f) that Recommendation X.213 describes the network service definition for open systems interconnectionfor CCITT
4、applications;(g) that Recommendation X.305 describes functionalities of subnetworks relating to the support of the OSInetwork service;(h) that the Q.1000 series of Recommendations define public land mobile networks (PLMNs);(i) that the International Maritime Satellite Organization (INMARSAT) is curr
5、ently operating a maritimesatellite system designated as Standard-A providing voice, telex and data transmission services;(j) that new INMARSAT standards designated Standard-B (digital replacement/upgrade for Standard-A),Standard-C (low data rate messaging system) and Aeronautical (digital voice and
6、 data transmission system for aircrafts)will be brought into service;(k) the need for arrangements when interworking between mobile systems and PSPDNs for the provision ofdata transmission services,unanimously recommendsthat arrangements for the interworking between PSPDNs and mobile systems for the
7、 provision of datatransmission services be in accordance with the principles and arrangements specified in this Recommendation.CONTENTS0 Introduction1 Scope and field of application2 References3 Definitions4 Abbreviations5 General aspects6 Specific interworking arrangements7 International interworki
8、ng2 Fascicle VIII.6 - Rec. X.3240 IntroductionThis Recommendation is one of a set of Recommendations produced to facilitate considerations of interworkingbetween networks. It is based on Recommendation X.300, which defines the general principles for interworking betweenpublic data networks, and betw
9、een public data networks and other networks. Recommendation X.300 indicates inparticular how collections of physical equipment can be represented as “subnetworks“ for consideration in interworkingsituations.This Recommendation describes the interworking arrangements between mobile systems and PSPDNs
10、 for theprovision of data transmission services. These interworking arrangements should include all the capabilities as describedin Recommendation X.213.1 Scope and field of applicationThe purpose of this Recommendation is to describe the general arrangements for the interworking betweenPSPDNs and m
11、obile systems for the provision of data transmission services. These arrangements are applicable only tothe interworking involving transmission capabilities and not to interworking involving communication capabilities asdescribed in Recommendation X.300.2 References1 Recommendation X.3002 Recommenda
12、tion X.3013 Recommendation X.3024 Recommendation X.3055 Recommendation X.3256 Recommendation X.17 Recommendation X.28 Recommendation X.109 Recommendation X.1213 DefinitionsThis Recommendation makes use of the following terms defined in Recommendation X.300:a) transmission capability,b) communication
13、 capability,c) subnetwork functionality,d) data transmission service.4 AbbreviationsCSPDN Circuit switched public data networkDTE Data terminal equipmentISDN Integrated services digital networkPDN Public data networkPLMN Public land mobile networkPSPDN Packet switched public data networkPSTN Public
14、switched telephone networkFascicle VIII.6 - Rec. X.324 35 General aspectsThis Recommendation, in describing interworking arrangements between two subnetworks for the provision ofdata transmission services, adheres to the general principles of Recommendation X.300. The environments of these twosubnet
15、works are described in the following sections.5.1 PSPDNThe PSPDN provides packet switched data transmission services as defined in Recommendations X.1 and X.2for the provision of data transmission services, the PSPDN may be accessed by DTEs by the categories of access C andD as defined in Recommenda
16、tion X.10. In addition, the PSPDN may also be accessed via other networks, i.e., PSTN(X.10 category L, P), CSPDN (X.10 category K, O), PSPDN (Recommendation X.75), ISDN (Recommendation X.325),or mobile systems (this Recommendation). Private networks access the PSPDN via X.10 category of access D.5.2
17、 Public mobile systemThe public mobile system may either be a public land mobile network (PLMN) as defined inRecommendation Q.1001 on a mobile satellite system (MSS) such as the one operated by the International MaritimeSatellite Organisation (INMARSAT).The mobile system may provide packet switched
18、data transmission services as defined in Recommendations X.1and X.2.In the context of this Recommendation, DTEs may access the mobile system by the categories of access C and Das defined in Recommendation X.10.5.3 Specific aspects of public mobile systemsIn addition to the basic functions of network
19、s they share with other types of networks, public mobile systemshave specific functions related to the mobility of their users accessing the system via mobile stations.Mobile systems deal with the mobility of their users in one of two ways:a) by requiring the calling user to specify one of a small n
20、umber of zones as the location of the mobile user;b) by maintaining a data base containing the current location of each mobile station (called a location register inRecommendation Q.1001) and arranging for the interconnected fixed network(s) to route calls to anappropriate access point to the public
21、 mobile system. With such a mechanism, the calling user need not knowthe current location of the called mobile user.The first method (called designation method call routing to mobile users) is used in the public maritime mobilesatellite system where the mobile station may be in one of three satellit
22、e regions. The second method (called non-designation method call routing to mobile users) is typified by systems conforming to the Q.1000 series ofRecommendations.4 Fascicle VIII.6 - Rec. X.3245.4 Organisation of X-series Recommendations related to interworking between PSPDNs and public mobile syste
23、msSince mobile systems fall into the two categories mentioned in 5.3, two sets of Recommendations are necessaryto describe the associated interworking arrangements. The existing and planned structure of these Recommendations isgiven in Figure 1/X.324.6 Specific interworking arrangementsFor further study.See also Recommendations X.351, X.352 for the public mobile satellite system.7 International interworkingFor further study.
