1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T Y.1546 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (10/2014) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Quality of service and network p
2、erformance Hand-over performance among multiple access networks Recommendation ITU-T Y.1546 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middlew
3、are Y.200Y.299 Network aspects Y.300Y.399 Interfaces and protocols Y.400Y.499 Numbering, addressing and naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.
4、1199 Architecture, access, network capabilities and resource management Y.1200Y.1299 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 IPTV over
5、 NGN Y.1900Y.1999 NEXT GENERATION NETWORKS Frameworks and functional architecture models Y.2000Y.2099 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.
6、2299 Enhancements to NGN Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Packet-based Networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 FUTURE NETWORKS Y.3000Y.3499 CLOUD COM
7、PUTING Y.3500Y.3999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.1546 (10/2014) i Recommendation ITU-T Y.1546 Hand-over performance among multiple access networks Summary Ubiquitous wireless access to IP-based networks in many areas raises the scenario of mult
8、iple communications opportunities, possibly among both free and subscription network services. Recommendation ITU-T Y.1546 provides common reference events and parameters for attachment and hand-over performance. The mapping between the set of common events and technology-specific protocol events ar
9、e provided in Annex A and Annex B, and these will be expanded as needed. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T Y.1546 2014-10-29 12 11.1002/1000/12328 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, fol
10、lowed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T Y.1546 (10/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technolo
11、gies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommu
12、nication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas
13、of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operat
14、ing agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“
15、 or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practi
16、ce or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation developm
17、ent process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore
18、 strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T Y.1546 (10/2014) iii Table of Contents Page 1 Scope . 1 2
19、References . 2 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 3 5 Conventions 4 6 Reference events . 4 6.1 Reference events at the user device (or other key location) . 4 7 Performance parameters . 4 7.1 Communication access pa
20、rameters . 5 7.2 Communication hand-over parameters . 6 7.3 User information transfer parameters . 7 7.4 Communication disengagement parameters . 7 Annex A Mapping of reference events to IEEE 802.11 wireless LAN 8 Annex B Mapping of reference events to 3GPP TS 23.401 . 10 Bibliography. 11 Rec. ITU-T
21、 Y.1546 (10/2014) 1 Recommendation ITU-T Y.1546 Hand-over performance among multiple access networks 1 Scope This Recommendation defines IP-layer and sub-IP-layer performance parameters for communication scenarios where one or more network technologies provide the access path between a users communi
22、cation device and an IP-based network (the Internet is the most common example), where the number of access paths to the IP-based network is changing (possibly due to mobility or to other factors such as failure or overload). The performance parameters defined here build on the foundation of point-t
23、o-point parameters defined in ITU-T Y.1540 and point-to-multipoint parameters defined in ITU-T Y.1544. One way to view the coverage of this Recommendation in comparison with ITU-T Y.1540 is to view them both in the context of the 3-by-3 matrix of communication phases and performance categories of sp
24、eed, accuracy and dependability. Table 1 Coverage of ITU-T Y.1540 Function/Criteria Speed Accuracy Dependability Activation Information transfer ITU-T Y.1540 packet transfer performance parameters Deactivation Whereas ITU-T Y.1540 covers the important phase of communication when the user device has
25、activated a network interface and performed sub-IP layer and IP layer configurations, this Recommendation recognizes the importance of metrics for access network activation and deactivation corresponding to a user devices mobility into and beyond coverage areas, and the policy of a user device to us
26、e access networks it deems suitable. Furthermore, this Recommendation recognizes that when more than one access network is accessible to the user device, the device policy may be to: hand-over communications to one network and deactivate others; prefer one access network but keep the other networks
27、active or in back-up/standby; use the information transfer capabilities of all networks simultaneously. New performance parameters are needed to accommodate all the policies above. At the core of hand-over performance is the simple activation speed and accuracy of the newly accessible network, follo
28、wed by the implementation of policy, or policy action followed by deactivation. Policy implemented before activation, based on a priori knowledge or field strength measurements is beyond the scope of this Recommendation. This phase of operation is often referred to as access network “discovery“. Thu
29、s, this Recommendation recognizes policy as an element of activation, prior to hand-over or possibly precluding hand-over when all information transfer capabilities will be used simultaneously. 2 Rec. ITU-T Y.1546 (10/2014) Table 2 Coverage of this Recommendation Function/Criteria Speed Accuracy Dep
30、endability Activation This Recommendation Policy decision (User device or network or negotiation by both) Hand-over This Recommendation Information transfer ITU-T Y.1540 packet transfer performance parameters Deactivation This Recommendation Table 3 Topics for further study Function/Criteria Speed A
31、ccuracy Dependability Activation (for 1 individual access networks) Simultaneous activation Information transfer Multipath/multi-access packet transfer performance parameters Deactivation Simultaneous deactivation 2 References The following ITU-T Recommendations and other references contain provisio
32、ns which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibilit
33、y of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendati
34、on. ITU-T I.350 Recommendation ITU-T I.350 (1993), General aspects of quality of service and network performance in digital networks, including ISDNs. ITU-T Y.1540 Recommendation ITU-T Y.1540 (2011), Internet protocol data communication service IP packet transfer and availability performance paramet
35、ers. ITU-T Y.1544 Recommendation ITU-T Y.1544 (2008), Multicast IP performance parameters. 3GPP TS 23.401 3GPP TS 23.401 (2014-06), General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access, ver. 12.5.0. IEEE 802.11 IEEE Std 802.11- 2012
36、, IEEE Standard for Information technology Telecommunications and information exchange between systems Local and metropolitan area networks Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. 3 Definitions 3.1 Terms defined elsewhere None.
37、 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: Rec. ITU-T Y.1546 (10/2014) 3 3.2.1 accessible network: An access network which, either recognizes the user device as participating in a subscription, has permission or which requires terms and conditions that
38、 the user has or will accept. 3.2.2 coverage definitions of overlaps and gaps Wireless networks provide variable coverage areas due to many factors including transmission power restrictions, radio antenna location and transmission obstacles in the line-of-sight between antennae. 3.2.2.1 coverage gap
39、: When a user device is unable to receive signals from (or send signals to) an accessible network, then this device is located in a coverage gap and all means of IP packet transfer are unavailable (according to the ITU-T Y.1540 definition of service availability). 3.2.2.2 overlapping coverage area:
40、When a user device is able to receive signals from and send signals to more than one accessible network, then this device is located in an overlapping coverage area and IP packet transfer service may be available (according to the ITU-T Y.1540 definition of service availability) from more than one t
41、ype of network or more than one network operator. 3.2.2.3 single coverage area: When a user device is only able to receive signals from and send signals to a single accessible network, then this device is located in a single coverage area and IP packet transfer service may be available (according to
42、 the ITU-T Y.1540 definition of service availability). 3.2.3 subscriber: An entity (associated with one or more users) that is engaged in a subscription with a service provider. The subscriber is allowed to subscribe and unsubscribe to services, to register a user or a list of users authorized to en
43、joy these services, and also to set the limits relative to the use that associated users make of these services. There may be data transfer limits on a subscription. There may be multiple devices used as part of the subscription. NOTE This Recommendation focuses on a single device. 3.2.4 user device
44、: A generic version of names for “mobile station“ (MS) and “user equipment“ (UE) used in other standards bodies. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: DNS Domain Name Service DHCP Dynamic Host Configuration Protocol HA Host Activation HC Host
45、 Connect HR Host Release HT Host Termination LA Link Attach LC Link Connect LR Link Release LT Link Termination MP Measurement Point MS Mobile Station UE User Equipment 4 Rec. ITU-T Y.1546 (10/2014) 5 Conventions None. 6 Reference events This clause defines the critical reference events for network
46、activation and deactivation. network discovery (sub-IP layer event) and activation start; IP network configuration complete; network rejection; network activation attempt time-out. 6.1 Reference events at the user device (or other key location) This clause proposes two sets of reference events at un
47、ified measurement points (MPs) for IP and sub-IP layer events. Ingress and egress measurement points allow observation of both directions of transmission for IP and sub-IP layer packets. 6.1.1 Ingress MP at sub-IP layer (L= link) Sub-IP connect reference event (LC): Occurs when a sub-IP packet ingre
48、ss event occurs, and the packet is a request to attach to a particular access network. Sub-IP release reference event (LR): Occurs when a sub-IP packet ingress event occurs, and the packet is a request to release resources on a particular access network. 6.1.2 Egress MP at sub-IP layer Sub-IP attach
49、 reference event (LA): Occurs when a sub-IP packet egress event occurs, and the packet confirms attachment to a particular access network. Sub-IP termination reference event (LT): Occurs when a sub-IP packet egress event occurs, and the packet acknowledges a request to release resources on a particular access network. 6.1.3 Ingress MP at IP layer (H=host, associated with a sub-IP layer) Host Config reference event (HC): Occurs when an IP packet ingress event occurs, and the
