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Multimedia Messaging
KRnet 2003
Jun-Won Lee E-mail : jlee@nablecomm.com
KRnet 2003 - Multimedia Messaging 2
목 차
메시징 서비스
메시징 관련 표준
IMS – Naming / Addressing / Routing
IMS – Presence Service
IMS – Group Management
Push-to-Talk 서비스 개요
Push-to-Talk 서비스 업계 동향
Push-to-Talk 서비스 구조 및 GUI 샘플
KRnet 2003 - Multimedia Messaging 3
메시징 서비스 (1)
SMS Perceived as being a real time service
Real time delivery cannot guaranteed
MMS
Based on SMTP(non real time)
Forward msg to the mail box not to the recipient
All media types available : text, images, audio, video
Instant
Messaging
Real time / Primarily text-based / presence services
May store msg if recipient unavailable (SMS-like)
Chat Private/Public chat rooms
One send text to a central point, distribute to others
E-mail Most popular method of messaging available today
Similar delivery mechanism as MMS (non real time)
KRnet 2003 - Multimedia Messaging 4
메시징 서비스 (2)
Immediate Delivery Messaging • In (near) real time
• Prior awareness of the availability of the recipient(s)
1) Pager Mode Messaging
Messages are Independent of each other
SIP MESSAGE method
2) Session-Mode Messaging
Message Session Relay Protocol (MSRP) : Mechanism for
transmitting session-mode messages with minimalist relay
support
E.g., chat room
Deferred Delivery Messaging • Reliable transfer of message guaranteed
KRnet 2003 - Multimedia Messaging 5
메시징 관련 표준 (1)
IETF • IMPP(Instant Messaging and Presence Protocol) WG
Goal : define a standard protocol so that independently developed applications of instant messaging and presence can interoperate
RFC2779 : a minimal set of requirements for IM and Presence
RFC2778 : a model of presence and instant messaging
• SIP(Session Initiation Protocol) WG
RFC3265, Session Initiation Protocol (SIP)-Specific Event Notification
RFC3428, Session Initiation Protocol (SIP) Extension for Instant Messaging
• SIMPLE(SIP for Instant Messaging and Presence Leveraging Extensions) WG
draft-ietf-simple-presence-10.txt, A Presence Event Package for the Session Initiation Protocol (SIP)
KRnet 2003 - Multimedia Messaging 6
메시징 관련 표준 (2)
(앞에서 계속)
• MSN messenger has support for SIP
• AOL will support SIMPLE for interoperability with other IM
applications
Wireless Village • Now part of Open Mobile Alliance(OMA)
• IMPS(Instant Messaging and Presence Service)
Now version 1.2 available
WAP and HTTP based
Only for wireless now
No seamless interoperation with other IM applications
• Started working on IMPS 2.0
Considering CPIM and SIMPLE support
KRnet 2003 - Multimedia Messaging 7
메시징 관련 표준 (3)
3GPP IMS(IP Multimedia Subsystem) • Including the elements necessary to support IP Multimedia(IM)
services
• Based on the IETF defined SIP protocol
• Purpose
Convergence of, and access to voice, video, messaging, data
and web-based technologies for the wireless user
Combine the growth of the Internet with the growth in mobile
communications
• ISC (IMS Service Control Interface)
Interface between S-CSCF and service platforms
Protocol to be used on ISC shall be SIP(RFC3261)
KRnet 2003 - Multimedia Messaging 8
IMS – Naming / Addressing / Routing (1)
Identification of users • Private user identities
NAI(network access identifier) : RFC2486
• Public user identities
SIP URL or TEL URL format
Routing of signaling within the IMS • Use SIP URIs or AbsoluteURI(RFC 2396)
• E.164 format shall not be used
Session request based on E.164 format require conversion into
SIP URL for internal IMS usage
E.164 address to SIP-URI resolution • Using ENUM DNS translation mechanism
• If failed, the session may be routed to the PSTN
KRnet 2003 - Multimedia Messaging 9
IMS – Naming / Addressing / Routing (2)
Public service identities • Identify services
presence, messaging, conferencing, etc.
E.g sip:chatlist_X@example.com
• Users establish a session to the „public service identity‟ to be able to
send and receive messages from other session participants
• Hosted by AS(application servers)
• IM CN shall be able to route IMS messages using „public service
identities‟
KRnet 2003 - Multimedia Messaging 10
IMS – Presence Service (1)
Presence
CS domain IMS
PS domain
Internet
Visited networks
Other networks
Home Environment
Voice services
Data services
Supplementary services
Multimedia services
Presence-enhanced
Ab
str
ac
t en
titi
es
KRnet 2003 - Multimedia Messaging 11
IMS – Presence Service (2)
Standard Documents • TS 22.141 v6.2.0, Presence service; Stage 1
• TS 23.141 v6.2.0, Presence service; Architecture and functional description
Presence Service • Targeting Wireless-enhanced version (e.g., using location
information)
• Provides ability for the home network to manage presence information of a user‟s device, service or service media even whilst roaming
Presentity • Representing a user
• Representing an abstract service or application
Road traffic information, sports results, news headlines
KRnet 2003 - Multimedia Messaging 12
IMS – Presence Service (3)
User Status Available
Not a vailable
Discreet
Invisib le
Location City
Coun try
Mark’s Presentity
Access Rules
My name is Mark and I am supported by the presence service. I have a presentity which represents me, and I am the principal of my presentity. As the principal, I supply
information to my presentity.
My presentity consists of information (describing my ability and willingness to communicate) and access rules (describing how my presence information
may be accessed).
Principal and presence information as a presentity
KRnet 2003 - Multimedia Messaging 13
IMS – Presence Service (4)
Presence Service Model
PRESENCE SERVICE
PRESENTITY
FETCHER
Fetcher requests the current
value of some Presentity’s
presence information from the
Presence Service
SUBSCRIBED-
WATCHER
Subscribed-watcher is a Watcher that
requests notification of (future) changes
in some Presentity’s presence
information from the Presence Service
POLLER
A Poller is a Fetcher that
requests the current value of
some Presentity’s presence
information from the Presence
Service on a regular basis.
WATCHER
KRnet 2003 - Multimedia Messaging 14
IMS – Presence Service (5)
Presence Information
PRESENCE INFORMATION
.
.
.
PRESENCE TUPLE
STATUS
COMMUNICATION ADDRESS
OTHER MARKUP
PRESENCE TUPLE
OTHER PRESENCE MARKUP
COMMUNICATION ADDRESS
STATUS
Contact address
Communication means
PRESENCE TUPLE
STATUS
COMMUNICATION ADDRESS
OTHER MARKUP
PRESENCE TUPLE
OTHER PRESENCE MARKUP
COMMUNICATION ADDRESS
STATUS
Contact address
Communication means
KRnet 2003 - Multimedia Messaging 15
IMS – Presence Service (6)
Item Explanation Example Values
Status Current condition of the
device or service represented
by the presence tuple
Open, closed, online,
offline, busy, away, do
not disturb, etc.
Item Explanation Example Values
Communication
means
A method whereby
communication can take
place
Service type(e.g.
telephony, SMS),
media type(e.g., audio,
text, video, multimedia
messaging service etc.
Status A specific point of contact via
some communications means
E.164, URI, inbox
address, etc.
Presence Information
KRnet 2003 - Multimedia Messaging 16
IMS – Presence Service (7)
A user’s presence information obtained from 1) The user
2) Information from supplied by network entities
3) Inforrmation supplied by elements external to the home network
(Reference Architecture 참조)
KRnet 2003 - Multimedia Messaging 17
IMS – Presence Service (8)
Reference Architecture
Interfaces Ph, Pi, Pc, Pg, Pk and Pl are based on existing R5
procedures e.g. CAMEL, MAP, CAP, RADIUS, ISC, Cx, Sh.
PeuPresence User agent
(Presence information
provided by the user)
Presence Network agent
(Presence information
provided by the network)
Pen
Pi
MSC Server
/VLRSGSN GMLC
Ph Pc Pg
Presence suppliers
Presence server
(home network)
Presentity
Presence Proxy
Watcher
Presence Proxy
Watcher
applications
HSS
(HLR)Pw
Pw
Pw
Px
GGSNS-CSCFHSS/HLR
Pk Pl
Presence External agent (Presence
information provided by elements
outside the provider’s network)
Pex
KRnet 2003 - Multimedia Messaging 18
IMS – Presence Service (9)
Watcher
application
Px = Cx
P-CSCF S-CSCF
I-CSCF
S-CSCFPresence
Server
Presentity Presence
Proxy
HSS
Pw = ISC
Pw =Mw
Watcher Presence Proxy
Pw = Gm
Application
Server
(Presence
List)
ISC
Watcher
application
Pw = ISC
Relationship of Presence Proxies with IMS entities
KRnet 2003 - Multimedia Messaging 19
IMS – Presence Service (10)
A Party Network B Party Network
A WA - A
Watcher
Presence
Proxy
1. Presence enquiry for B
3. Presence enquiry for B
2
5. Presence enquiry for B
10a. B party
status sent to
IPP
4.
11. B’s presence status to A
8, 9
Presentity
Presence
Proxy
6. Presentity Presence Proxy
derives address of B’s presence
server
7. Presence enquiry for B
PS - B HLR/HSS
10b. B party status sent
to Watcher Presence
Proxy
10c. B party
status sent to
WA-A
KRnet 2003 - Multimedia Messaging 20
IMS – Presence Service (11)
Charging Requirements (not exhaustive) • Watcher Presence Proxy provides charging information for
Presence enquiry or subscription and subsequent notifications
• Presence Server provides charging information for
publishing presence information
Subscription to watcher lists
…
KRnet 2003 - Multimedia Messaging 21
IMS - Group Management (1)
IMS Group Management • 3GPP TS 22.250 (Release 6)
• Provides possibility to manage network based groups
• Can be utilized together with several different group related services
Conference calls, Presence service, Messaging, etc.
Messagingserver
Delivery
list:
Paul
Lena
Lisa
I want to send a message to Paul,
Lena and Lisa. To optimise the
radio interface traffic I will utilise
messaging server to do the
distribution
Use IMS group
management to create
message delivery list
Paul
Lena
Lisa
Message
Message
Mes
sage
Message
Messagingserver
Delivery
list:
Paul
Lena
Lisa
I want to send a message to Paul,
Lena and Lisa. To optimise the
radio interface traffic I will utilise
messaging server to do the
distribution
Use IMS group
management to create
message delivery list
Paul
Lena
Lisa
Message
Message
Mes
sage
Message
KRnet 2003 - Multimedia Messaging 22
IMS - Group Management (2)
Group Information • Group Identifier
• Group Specific Information
Group Information
Group Properties (visibility / duration)
• Service Specific Information
How the group be used in the context of a specific service
Access list in the context of presence service
Delivery list in the context of messaging service
KRnet 2003 - Multimedia Messaging 23
IMS - Group Management (3)
Capabilities to manage groups • Create(delete) a group
• Add(remove) members to(from) a group
• Get member list of a group
• Get group member identification(or properties)
• Modify group member properties
• Get group(or service) specific information
• Modify group(or service) specific information
• Simultaneous access from multiple terminals
• Search
Notification • In the event of group information change
KRnet 2003 - Multimedia Messaging 24
IMS - Group Management (4)
Charging • Pay per transaction
• Volume based charging
Volume of transferred group content
• Indirect charging
When it is incorporated as part of a service
KRnet 2003 - Multimedia Messaging 25
Push-To-Talk 개요 (1)
PTT는 다음 서비스와 유사함
• TRS
그룹 통신 지원
특정 순간에 한 사람만 발언할 수 있음
버튼을 눌러서 발언권 획득 후 발언
신속성, 즉시성이 강조되는 통신 방법
기지국을 통한 릴레이 기능으로 지리적 제한이 없음
• Instant Messenger (IM)
친구 및 조직도 관리
Buddy의 프레즌스 정보 공유
즉시 통신, 그룹 통신
KRnet 2003 - Multimedia Messaging 26
Push-To-Talk 개요 (2)
TRS, IM에 비해 PTT의 장점 • TRS는 비표준의 기지국을 전용망으로 구축해야 하므로 구축 비용이 높은 데
반해, VoIP 기반의 PTT는 CDMA1x, EV-DO, WLAN 등 유무선 IP 인프라를 활용하므로 구축 비용이 낮음
• TRS는 비표준의 전용단말기를 사용해야 하므로 단말기 가격이 비싸고, 크고,
디자인이 투박하며 단말기 선택의 폭이 작은데 반해, PTT는 휴대폰, PDA, PC
등 다양한 IP 단말기에 응용 형태로 구현할 수 있으므로 전용단말기 구매 필요성이 없음
• TRS는 기지국 수가 작아서 지하, 도심 외 지역에서는 통화가 되지 않으므로
TRS 단말기 외에 휴대폰을 별도로 소지해야 하는데 반해 PTT는 이미 구축된
IP 인프라를 활용하므로 음영지역이 아주 작음
• TRS는 그룹 구성원 설정이 제한적이며 프레즌스 정보 확인이 불가한데 반해,
PTT는 인스턴트 메신저처럼 프레즌스 정보를 가시적으로 보일 수 있음
• 인스턴트 메신저를 휴대단말기에 적용할 경우, 문자 입력이 불편한 데 반해
PTT는 텍스트 외에 음성을 이용할 수 있으므로 무선 메신저 서비스에 적합
• Video 등 멀티미디어 통합이 용이함
KRnet 2003 - Multimedia Messaging 27
Push-To-Talk 개요 (3)
Presence-based PTT (Push-to-Talk) 서비스 시스템
• All-IP 기반의 유, 무선 인터넷 환경에서 음성 및 텍스트 기반의 일대일 및 그룹
즉시 통신(instant communication) 서비스를 제공하기 위한 시스템
주요 기능
• Buddy list 및 그룹 관리
• 프레즌스 관리
• 1:1 및 1:N instant voice communication
• 1:1 및 1:N instant text communication(IM)
표준
• Call control protocol : SIP
• Media stream protocol : RTP, RTCP
• Presence management protocol : SIMPLE
• System management and provisioning : SNMP
KRnet 2003 - Multimedia Messaging 28
Push-To-Talk 개요 (4)
기능 및 도입 효과
• 1:1 및 그룹 (1:n)간 동시통화 조직 내 신속한 의사전달 및 의사결정
• 조직 구성원간 프레즌스 정보 공유 협업을 통한 효율성 제고
주요 활용 사례
• 운송/창고/제조업체의 현장-사무실간 통신
• 유통 (할인점 등) 현장에서의 통신
• 빌딩 내 팀원간 즉시 통신
• 영업, 현장 A/S 등 신속한 업무 처리
• 병원 등 의료기관 내에서의 신속한 통보/조치
• 놀이공원/위락시설 등에서의 구내무선통신
• 게임
• 텔리매틱스
KRnet 2003 - Multimedia Messaging 29
PTT 업계 동향 (1)
Nextel Communications
• 서비스 명 : “Direct Connect”
• 2001년 당시 7.2 M subscribers
• 일인당 평균 월 사용요금 : $72(타 이통사 평균 : $45)
• 가장 낮은 서비스 이탈율(2.1%)
• 현재 Motorola iDEN(integrated dispatch enhanced network) 방식
• VoIP 기반 PTT 방식 추진
Qualcomm 과 미국 내 독점 계약
Verizon Wireless, Sprint PCS, AT&T Wireless
• 2003년 중 PTT 서비스 개시 선언
• VoIP 기술 기반
Ericsson, Nokia, Siemens
• PTT 표준화 공동 추진
KRnet 2003 - Multimedia Messaging 30
PTT 업계 동향 (2)
Ericsson
• “InstantTalk”
• PTT demonstration at CTIA Wireless 2003
• Over CDMA2000 and GSM/GPRS
• IMS-based
가입자수 예측(Strategis Group, ADL)
• 17M subscribers by 2004 in America
• From 3M today to 9.5M by 2005 in Europe
KRnet 2003 - Multimedia Messaging 31
기술 표준
SIP
• RFC3261(SIP : Session Initiation Protocol)
• Call and session control
SIMPLE
• RFC3265 (SIP - Specific Event Notification)
• Presence management
• Instant messaging
RTP
• RFC1889(A transport protocol for real time applications)
• Real time data transport
• Voice and video
KRnet 2003 - Multimedia Messaging 32
주요 기술
그룹 세션 관리
• 유연한 그룹 정의 및 관리
사전 정의 그룹
Ad-hoc 그룹 정의
멤버 추가 및 삭제
• 그룹 세션 설정 및 해지
발언권 제어
• 다양한 발언 우선 순위 제어
RTP 미디어 릴레이
• RTP 패킷 릴레이 및 멀티캐스트
• RTP over UDP/TCP
KRnet 2003 - Multimedia Messaging 33
PTT 서비스 구조
SIP Proxy Server
(or KT Softswitch)
PTT Client (PC)
PTT Application
Server
SIP
PTT Client
(Cellular Phone)
PTT Relay
Server
SIP
RTP Stream
Presence
Server
SIP signaling
RTP Stream
Public Wireless Network
(CDMA1X, EV-DO)
Hotspot area
(WLAN Network)
OAM Server
KRnet 2003 - Multimedia Messaging 34
PTT GUI Sample (1)
User Interface - Presence
Push to talk start button
Multiple choice box
to select participants
Buddy list view
우리팀 (3/4)
팀장 (전화중)
팀원1 (오프라인)
팀원2
팀원3
기타
회사 (57)
CEO (1)
마케팅본부 (20)
마케팅본부장
마케팅1 (오프라인)
마케팅전략팀 (5)
마케팅2 (오프라인)
내상태 - 온라인
KRnet 2003 - Multimedia Messaging 35
PTT GUI Sample (2)
User Interface – PTT Group Session
Text Instant Messaging Window
Session participant view
팀장
팀원2
팀원3
Session1 - 대기중
KRnet 2003 - Multimedia Messaging 36
Thank You !!!
E-mail : jlee@nablecomm.com
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