1、 International Telecommunication Union ITU-T Y.3043TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (08/2013) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Future networks Smart ubiquitous networks Context awareness framework Recommendation ITU-T
2、Y.3043 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 middleware Y.200Y.299 Network aspects Y.300Y.399 Interfaces and protocols Y.400Y.499 Numberi
3、ng, 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.1199 Architecture, access, network capabilities and resource management Y.1200Y.1299
4、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 NGN Y.1900Y.1999 NEXT GENERATION NETWORKS Frameworks and functional architecture mod
5、els 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.2299 Enhancements to NGN Y.2300Y.2399 Network management Y.2400Y.2499 Network control
6、 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.3499CLOUD COMPUTING Y.3500Y.3999 For further details, please refer to the list of ITU-T Recommendat
7、ions. Rec. ITU-T Y.3043 (08/2013) i Recommendation ITU-T Y.3043 Smart ubiquitous networks Context awareness framework Summary Recommendation ITU-T Y.3043 describes the framework of context awareness for smart ubiquitous networks (SUN). It also addresses the concept of context awareness as a key capa
8、bility of SUN. It further specifies requirements based on key characteristics of context awareness. In addition, key functionalities to support context awareness including architectural model and related context awareness mechanisms are also identified. For a better understanding of context awarenes
9、s for SUN, relevant use cases are described in Appendix II. History Edition Recommendation Approval Study Group 1.0 ITU-T Y.3043 2013-08-13 13 Keywords Context awareness, SUN. ii Rec. ITU-T Y.3043 (08/2013) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized ag
10、ency in the field of telecommunications, information and communication technologies (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 vie
11、w to standardizing telecommunications on a worldwide basis. The World Telecommunication 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 Recommendat
12、ions is covered by the procedure laid down in WTSA Resolution 1. In some areas 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 concisen
13、ess to indicate both a telecommunication administration and a recognized operating 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 Recommendatio
14、n is achieved when all of these mandatory provisions are met. The words “shall“ 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. INT
15、ELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice 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,
16、whether asserted by ITU members or others outside of the Recommendation development 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 ar
17、e cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2014 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permissi
18、on of ITU. Rec. ITU-T Y.3043 (08/2013) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 Overview of context awareness for SUN . 3 7 Requirements to support
19、context awareness for SUN 4 7.1 General requirements for context awareness 4 7.2 Specific requirements for context delivery . 5 8 Functional model and architecture to support context awareness in SUN . 5 8.1 Functional model for context awareness 5 8.2 Functional architecture for context awareness i
20、n SUN 6 9 Context awareness mechanisms . 8 9.1 Context gathering mechanisms . 8 9.2 Decision-making scheme for context prediction 8 10 Operations model of context awareness in SUN 10 11 Security considerations . 10 Appendix I Types of context sources (entities) for context awareness . 11 Appendix II
21、 Applications and use case of context awareness 12 II.1 Applications of context awareness . 12 II.2 A use case of context awareness context aware content delivery services . 13 Bibliography. 15 Rec. ITU-T Y.3043 (08/2013) 1 Recommendation ITU-T Y.3043 Smart ubiquitous networks Context awareness fram
22、ework 1 Scope Context awareness has been identified as one of the key capabilities of smart ubiquitous networks (SUN) ITU-T Y.3041. This Recommendation describes the framework of context awareness for SUN. This Recommendation covers the following: general overview of context awareness for SUN includ
23、ing key characteristics; requirements to support context awareness for SUN; key functionalities to support context awareness, including the architectural model; context awareness mechanisms. 2 References The following ITU-T Recommendations and other references contain provisions which, through refer
24、ence 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 possibility of applying the most
25、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 Recommendation. ITU-T Y.2201 Recomm
26、endation ITU-T Y.2201 (2009), Requirements and capabilities for ITU-T NGN. ITU-T Y.2701 Recommendation ITU-T Y.2701 (2007), Security requirements for NGN release 1. ITU-T Y.3041 Recommendation ITU-T Y.3041 (2013), Smart Ubiquitous Networks Overview. 3 Definitions 3.1 Terms defined elsewhere This Rec
27、ommendation uses the following terms defined elsewhere: 3.1.1 context b-ITU-T Y.2002: The information that can be used to characterize the environment of a user. NOTE Context information may include where the user is, what resources (devices, access points, noise level, bandwidth, etc.) are near the
28、 user, at what time the user is moving, interaction history between person and objects, etc. According to specific applications, context information can be updated. 3.1.2 context awareness ITU-T Y.2201: Context awareness is a capability to determine or influence a next action in telecommunication or
29、 process by referring to the status of relevant entities, which form a coherent environment as a context. 3.1.3 smart ubiquitous networks (SUN) ITU-T Y.3041: IP-based packet networks that can provide transport and delivery of a wide range of existing and emerging services to people and things. The s
30、ervices provided by the SUN can cover aspects such as control, processing and storage. NOTE 1 The network is smart in the sense that it is knowledgeable, context-aware, adaptable, autonomous, programmable, and can perform services effectively and securely. 2 Rec. ITU-T Y.3043 (08/2013) NOTE 2 The ne
31、twork is ubiquitous in the sense that it allows access anytime, anywhere, through varied access technologies, access devices, including end-user devices, and human-machine interfaces. 3.2 Terms defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation uses the following a
32、bbreviations and acronyms: BGP Border Gateway Protocol CA-FE Context Analysis Functional Entity CCG-FE Content Context Gathering Functional Entity CD-FE Context Delivery Functional Entity CF-FE Context Filtering Functional Entity CGF Context Gathering Function CMAF Context Management and Analysis Fu
33、nction CP-FE Context Prediction Functional Entity CPU Central Processing Unit CR-FE Context Request Functional Entity CR User device context gathering functional entity (DCG-FE) for gathering context information from user device context such as environment context (e.g., time, location and physical
34、phenomena); Network context gathering functional entity (NCG-FE) for gathering context information from the network (e.g., resource status of network); Service context gathering functional entity (SCG-FE) for gathering service related context information (e.g., service types); Content context gather
35、ing functional entity (CCG-FE) for gathering content related context information (e.g., content types, codec) from content server. Context management and analysis function (CMAF): The CMAF performs the filtering of context information, analyses the raw data for context awareness and provides predict
36、ed information based on the context repository and the knowledge base. Context filtering functional entity (CF-FE): The CF-FE classifies the raw data gathered from context sources and changes them to the available format used for context analysis, context prediction. In addition the CF-FE sends them
37、 to the CA-FE for context analysis or to appropriate repositories for future use. Context analysis functional entity (CA-FE): The CA-FE manipulates raw context information to create more composite and semantically rich information in support of context repository and knowledge base. Then, the create
38、d data become meaningful contextual knowledge required by context users. Context prediction functional entity (CP-FE): The CP-FE tries to predict the future context for context users based on the result of context analysis and provides preventive approach to prepare for upcoming situation. 8 Rec. IT
39、U-T Y.3043 (08/2013) Context repository: The context repository provides historical data for making decisions based on historical observations. A distributed design for context repository in order to achieve scalability is considered: A centralized context repository in a centralized context awarene
40、ss system and locally distributed context repositories from various context sources. Knowledge base: An information repository that provides a means for information to be collected, organized, shared and utilized for context awareness. It contains a set of data including the information on SLAs and
41、policies, often in the form of rules that describe the knowledge in a logically consistent manner. An ontology can define the structure of stored data what types of entities are recorded and what their relationships are. Context request and context delivery function (CR dynamic information can chang
42、e over time depending on location, system condition or network traffic. Prediction on dynamic information is difficult since it depends on many other external factors. In addition, it requires study of previous information sets to predict the expected behaviour or results. For context prediction, Fi
43、gure 9-1 shows a scheme for decision-making based on context information with both static and dynamic nature of data. Rec. ITU-T Y.3043 (08/2013) 9 Y.3043(13)_F9-1Static profileUser indexPreference listDevice selectioncriteria1. Screen size2. Service interface3. Processor capacity4. Supporting codec
44、5. CPU and memoryContext change1. Change in location3. Action by the user(play, pause, stop)4. New service request2. Change in device5. Network failureDynamic profileNetwork indexNetwork propertiesNetwork selection criteria1. Network QoS (packetdelay, loss and jitter)2. Delivery medium3. Minimum ban
45、dwidth4. Network availability5. Network coverageDevice 1Device 2Device 3Network 1Network 2WeightingsTarget environmentFigure 9-1 Decision making scheme for context prediction In Figure 9-1, context information is gathered from the context sources (e.g., sensor around user) and sent to the context pr
46、ediction functional module (i.e., context predictor) which is located in a home network or an operator network. Figure 9-1 presents a few context changes like change in device, change in location, subscriber actions, network failures and new service requests coming into the system. There are situati
47、ons where a user is responsible for the events. In some cases, it can happen due to changes in environment and social interactions. The context predictor makes decisions based on selection criteria for devices, networks, etc. according to context changes. For a specific case, weightings based on pre
48、defined policy are used for adaptive prediction considering dynamic situations. NOTE For example, someone watching video content can carry the content over to a mobile device when moving away from the home or work place. Context awareness services are always responsible for delivering a continuous u
49、ninterrupted stream to the subscriber. However, implementation always demands correct context information to the context predictor which leads to taking correct decisions. Location change can demand a context predictor to find the best suited network to reach the expected QoE or handover between networks to reach the subscribers. Proper handling of context information immensely improves seamless service continuity. It is important to keep track of subscriber activitie
