Southern Methodist University Fall 2003 EETS 8316/NTU CC745-N Wireless Networks

1. Southern Methodist University Fall 2003 EETS 8316/NTU CC745-N Wireless Networks Lecture 12: EDGE Instructor: Jila Seraj email: jseraj@engr.smu.edu http://www.engr.smu.edu/~jseraj/ tel: 214-505-6303

2. Housekeeping • Exam 12/04 at 6:30 pm • Duration one hour • Distant students can take it anytime before 12/17. Please contact your proctor immediately. The exam is available from 12/04. • Homework #3 is on the web. Deadline Dec 5th for in-campus students and Dec 12th for others.

3. Outline • EDGE • Classic and Compact • GERAN

4. UE Review, UMTS Architecture CN CN : Enhanced GSM/GPRS CN RN: UTRAN Iu UTRAN Uu UTRAN UMTS Terrestrial Radio Access Network CN Core Network UE User Equipment

5. Application services 2G network Roaming GW HLR IP CSCF RAN 3G SGSN 3G GGSN PSTN GW Iu PSTN 3G MSC Review, UMTS reference model

6. Review, UMTS reference model • CSCF = Call State Control Function • responsible for call state control functions, service switching function, address translation, vocoder negotiation to support VoIP • Call state is a set of states identified in the process of completing a call. Obvious examples of call state are: Call attempt, Called number reception, Called number translation, Feature Activation, Called party Alert, through connection, Calling Party Release, etc…

7. Iub Iub Review, UTRAN Architecture Core Network Iu Iu RNS RNS Iur RNC RNC Iub Iub Node B Node B Node B Node B

8. Review, Functions of UTRAN Components • RNC • Uplink/downlink signal transfer, mobility, soft handoff • Upper outer loop/ downlink power control, • Common control channels • Very similar to BSC functions

9. Review, Functions of UTRAN Components • Node B: • Logical node, maintains link with UE • Responsible for radio transmission for one or more cells, adds/removes radio links on demand, • Mapping logical resources to physical resources, • Upper inner loop power control, • Interconnecting UE from different manufacturers. • Similar to BTS function

10. Review, UTRAN Interfaces • Uu: Between Node B and UE (WCDMA) • Iub: Between Node B and RNC (ATM) • Iur: Between various RNCs (ATM) • Iu: Between the Core Network and the RNC (IP over ATM)

11. Review, Protocol Model for UTRAN Interfaces • UTRAN consists of • Radio Network Layer (specific to UTRAN itself) • Transport Network Layer (standard technology: ATM)

12. Review, Protocol Model for UTRAN Interfaces • The UTRAN specific protocols include • Radio Access Network Application Part: Radio Network Signaling over the Iu. • Radio Network Subsystem Application Part: Radio Network Signaling over the Iur. • Iub interface uses node B application protocol (NBAP).

13. Review, UTRAN Interfaces • Iur Interface (RNC <-> RNC) • point-to-point open interface, • macro-diversity support, • transport signaling for mobility and radio resource allocation. Node B Iub RNC Iu Iur Node B RNC Node B

14. Review, UTRAN Interfaces • Iub Interface (RNC <-> Node B) • interconnection of equipment from different manufacturers, • allows Abis (GSM/GPRS transmission sharing), • transports DCH, RACH, FACH and DSCH data, • enables negotiation of radio resources between node B and RNC

15. EDGE • EDGE= Enhanced Data rates for Global Evolution • EGPRS = Enhanced General Packet Radio Services • EDGE is an enhancement to GPRS • Maximum of 473 kbps if all 8 time slots are used

16. EDGE • Introduces concept of “Link Adaptation” in wireless for maximum throughput in variable radio conditions • The data rates are tripled. The magic is in introduction of 8-PSK modulation that can carry 3 bits per symbols • 8-PSK = Octagonal Phase Shift Keying • EGPRS impact is mainly in RF and MAC

17. GSM EDGE Radio Access Network • GERAN = GSM EDGE Radio Access Network • Motivation • All IP Network • Low cost of operation • One platform • support of new services • Support for different access networks

18. Requirements GERAN • Spectrum efficient support for VoIP, (end-to-end IP-based voice service), Quality  TDMA • Support of new IP multimedia services, Future proof • Alignment with UMTS/UTRAN service classes and QoS • Common GPRS and GSM Core Network for EDGE and UTRAN

19. Requirements on GERAN .. • Integration of all services over IP infrastructure • Support for COMPACT and VoIP/COMPACT

20. 3G MSC 3G SGSN MSC Server SGSN Server MGW MGW GERAN GERAN connects to PS CN through Iu-ps for R4 and R5 terminals (New protocols) and Gb for R97 and R99 terminals (LLC and SNDCP protocols) Iu-ps Gb SGSNN GERAN TE MT BSS R Iu-cs Um A GERAN connects to CS CN through Iu-cs or A MSC

21. GERAN Interfaces • Gb • GPRS interface not suitable for RT transmission • LLC+RLC both ARQ protocols • IP instead of FR • Iu-ps • UTRAN PS, IP, QoS, AAL5/ATM , possibly IP over SDH

22. New Features in EGPRS Rel 4. • Delayed TBF Release • In bursty traffic, many call set up and release makes inefficient use of resources. By delaying release of TBF, and sending dummy LLC frames to mobile, the link is kept alive. • Network Assisted Cell Change (NACC) • When sending neighbour information, cell system information is also sent to mobile. When handing off, mobiles has all the data it needs. Speeds up handoff.

23. New Features in EGPRS Rel 5 • Delayed TBF Release • In bursty traffic, many call set up and release makes inefficient use of resources. By delaying release of TBF, and sending dummy LLC frames to mobile, the link is kept alive. • Network Assisted Cell Change (NACC) • When sending neighbour information, cell system information is also sent to mobile. When handing off, mobiles has all the data it needs. Speeds up handoff.

24. COMPACT System Concept • First 200 kHz carrier • 1/3 reuse. • CPBCCH (Compact Packet BCCH) Transmits discontinuously ( at certain time). • Synchronization of base stations and time split into four time groups provide an effective 4/12 reuse for broadcast and common control channels.

25. COMPACT System Concept • All Traffic and dedicated channels on the rest of TS are reuse 1/3. • Support for paging for TDMA/136 circuit switched. • Minimum deployment: 3 carriers, 0.6 MHz plus guard bands.

26. EDGE Compact • There is a Base station synchronization concept in GSM • GSM BTS synch is used only on the traffic channels TCH that has FH in Fractional loading planning (FLP)to avoid Co-channel and adjacent channel interference in reuse 1/3 and smaller. • The BCCH is transmitting continuously with 5/15 and higher reuse.

27. Reuse 1/3

28. Compact

29. Evolution of 2G Cellular Technologies 2G 3G IS-95B CDMA cdma2000 FDD GSM W-CDMA TDD GPRS EDGE & 136 HS outdoor IS-136 TDMA UWC-136 136 HS indoor

30. Quality-of-Service: What, Why? • Quality of Service (QoS) is the ability of a network element (e.g. an application, host or router) to have some level of assurance that its traffic and service requirements can be satisfied. • Newer applications with multimedia content • Demands of convergence • More bandwidth ? • User perception of service quality can be translated to network flow parameters such as delay and delay variation.

31. Guidelines for providing QoS to users • QoS perceived by the user must be end-to-end. • Parameters defining QoS of a flow must be fewer and simpler. • QoS definition must be compatible with all kinds of applications. • Must be able to quantify and enforce.

32. UMTS-specific requirements (contd.) • QoS parameter control on peer to peer basis between mobile and 3G gateway node • UMTS QoS control mechanism should map applications QoS profile to UMTS services. Applications may be required to state their QoS requirement. • UMTS QoS capable services should work with other networking architectures. • Only finite set of QoS definitions supported.

33. UMTS-specific requirements (contd.) • Multiple traffic streams per session. • Lower overhead for QoS related operations; higher resource utilization. • Re-negotiation should be possible after QoS parameter values have been agreed upon - dynamic QoS. • User mobility should be supported in the QoS framework.

34. Traffic cases for QOS • Conversational RT media, delay sensitive delay variation sensitive (VoIP, Conferencing,..) • Streaming Delay variations sensitive Audio and video relaxed absolute delay than conversational (buffering required)

35. Traffic cases for QOS • Interactive none real time, delay sensitive (WWW, ftp, remote databases, ..) • Background none RT (e.mail, SMS, ftp,..)

36. QoS attributes for Traffic Classes

37. 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 delay throughput retransmission QoS Characteristics of UMTS Classes Very important Conversational Streaming Interactive Background less important

38. QoS supported • Interactive supported in R99 • Background supported in R99 • Conversational R5 • Streaming R4

39. Useful Links • http://www.3gpp.org/TB/GERAN/GERAN.htm • http://www.3gpp.org/

40. WAP • Wireless Access Protocol (WAP • Started with Ericsson, Nokia and Motorola • WAP goal is • Open standards • Internet WWW application development model • Wireless network technology and bearer independence • Device independence • Embrace and extend existing standards

41. WAP (cont) • Strength • Widespread presentation • 90% of all handset manufacturers are committed • Carriers representing nearly 100 million subscribers worldwide have joined WAP

42. WAP (cont) • Why not adopt internet protocols? • Limitations of wireless handheld devices • Small display • Limited memory • Limited keyboard • Limitations of wireless networks • Limited bandwidth • High latency • Limited computing environment

43. Benefits of WAP • WWW-based applications • Interoperability across network types • Efficient use of wireless network resources

44. Key Features of WAP • Markup language • Script Language • Designed to create services for small handheld terminals • Wireless technology applications framework • Access to telephony related functions • Lightweight protocol stack • designed to minimize required bandwidth and impact on latency

45. Client Origin Server WAP User Agents CGI Scripts WAP Protocol Stack WML WMLcript WAP Architecture WAP Gateway/ Proxy WSP Request HTTP Request Encoders Decoders HTTP Response WSP Response Protocol Conversion

46. WAP Protocols and Standards • WAP stack design goal • Avoid establishment and tear down phases • Optimize for short request-response transactions • Support wide range of wireless networks • Datagram is the most common transport service • Minimize number of packets sent over the air • Moving data around is expensive • Avoid resending same (static) information

47. Wireless Session Protocol (WSP) HTTP Wireless Transaction Protocol (WTP) Wireless Transport Layer Security (WTLS) TLS-SSL UDP Wireless Datagram Protocol (WDP) UDP IP UDCP IP (ICMP) USSD SMS Etc GPRS CDPD WAP Protocols and Standards (cont)

48. WAP Protocols and Standards (cont) • Runs over wireless networks including GSM, SMS/USSD and IP networks • Has minimal requirements on bandwidth and CPU power • Is based on HTTP/1.1 with necessary enhancement

49. Wireless Application Environment (WAE) • Wireless markup language (WML) • Lightweight markup language similar to HTML. Optimized for hand-held mobile devices • WML script • Similar to Java Script, light weight scripting language

50. Wireless Application Environment (WAE) • Wireless Telephony Application (WTA, WTAI) • A framework and programming interface for telephony services • Wireless BitMaP (WBMP)