On the Road to UMTSOutlineWhat is GSM??GSM ArchitectureMobile StationBase Station SubsystemNetwork SubsystemSlide 8GSM FeaturesSlide 10GPRS SystemGPRS ArchitectureGPRS FeaturesSlide 14GPRS Features Cont.Slide 16Slide 17Slide 18EDGEEDGE FeaturesEDGE Features cont.Slide 22Slide 23Scenario for Migration from 2G to 3GWhat are 3G Technologies?What are 3G Technologies? Cont.To be ContinuedWhat does UMTS provide?UMTS coverage vs. bit rateSlide 30UTRAN-UMTS Terrestrial Radio Access NetworkFrequency AllocationFDD vs. TDDWCDMAWCDMA Radio ParametersWCDMA Performance ImprovementHCS & Hot-SpotWCDMA ChannelsSlide 39An Example of Channel GenerationWCDMA Convolutional EncoderWCDMA Block InterleavingWCDMA Orthoganal ModulationCDMA Orthoganal ModulationWCDMA Direct Sequence SpreadingSlide 46Power Control In WCDMASlide 48Slide 49Slide 50Slide 51WCDMA Soft HandoffActive Research TopicsSlide 54ReferenceSlide 56Copyright, 2000 © SUNY at Buffalo.On the Road to UMTSHongyi WuXiaojun Cao(Universal Mobile Telecommunications Service)Outline•Introduction to GSM•GPRS•EDGE•UMTS•WCDMA•SummeryWhat is GSM??(Global System for Mobile Communications)GSM Architecture•Three broad parts–Mobile Station (MS): carried by the subscriber–Base Station Subsystem: control radio link with MS–Network Subsystem: its main part is MSC•Interfaces: –Um Interface : known as air interface or radio link.–Abis Interface: between BTS and BSC–A Interface: between BSC and MSCMobile Station•ME(mobile equipment) –the terminal•SIM (Subscriber identity Module)–provides personal mobility. –Can insert the SIM card into another GSM terminal and useBase Station Subsystem•BTS (Base Transceiver Station)–handle the radio link protocols with the Mobile Station–many BTSs in a large urban area•BSC (Base Station Controller)–manages the radio resources for one or more BTSs–handles such as: channel setup , frequence hopping and handovers.–connection between MS and MSCNetwork Subsystem•MSC (Mobile Services Switching Center)–acts like a normal switching node of the PSTN or ISDN–provides the connection to the fixed networks (such as the PSTN or ISDN). •HLR (Home Location Register )–contains information of each subscriber registered in the corresponding GSM network, along with the current location of the mobile.–logically one HLR per GSM networkNetwork Subsystem cont.•VLR (Visitor Location Register) –contains selected information from the HLR, necessary for call control and provision of the subscribed services, –each mobile currently located in the geographical area controlled by the VLR. •EIR (The Equipment Identity Register) – a database that contains a list of all valid mobile equipment on the network, •AuC (The Authentication Center) –is a protected database:secret key of SIMGSM Features•Multiple access: use TDMA/FDMA to share the limited radio spectrum–The FDMA part involves the division by frequency of the (maximum) 25 MHz bandwidth into 124 carrier frequencies spaced 200 kHz apart.–Each of these carrier frequencies is then divided in time, using a TDMA scheme. •GSM is a digital network–Based on Circuit-switchGSM Features cont.•SMS: Short Message Service –is a bi-directional service for short (up to 160 bytes) messages. Messages are transported in a store-and-forward fashion.–an acknowledgement of receipt is provided to the sender. –can also be used in a cell-broadcast mode, for sending messages such as traffic updates or news updates. Messages can also be stored in the SIM card for later retrievalGPRS System(General Packet Radio Service)GPRS Architecture •Introduce two new nodes into GSM network–SGSN (the Serving GPRS Support Node): •Keep track of the location of the mobile within its service area and send/receive packets from the mobile , passing them on, or receiving them from the GGSN–GGSN (Gateway GPRS Support Node): •convert the GSM packets into other packet protocols (e.g.IP or X.25) and send them out into another network.GPRS Features•Log on to GPRS–A GPRS-capable terminal communicates with GSM base Stations, but unlike circuit-switched data calls which connects to MSC, GPRS packets are sent sent from the base station to SGSN, SGSN communicates with GGSN.–Establishes a Packet Data Protocol (PDP) which is logical connection between the mobile and GGSN–now visible to the outside fixed networksGPRS Features Cont.–SGSN and GGSN use GPRS tunnel protocol (GTP) which operates over the top of TCP/IP to encapsulate the packets –Tunnels: information may be encrypted and additional data is added to each packet to prevent tampering•Packed based–No dial-up, just as with a LAN connection.–No delay for sending dataGPRS Features Cont.–pay for the amount of data they actually communicate, and not the idle time –users need to confirm their agreement to pay for the delivery of content from the service. This is performed by using WAP (Wireless Application Protocol)–unsolicited packets may not be charged–voice and Data Communication at the same time–can be viewed as a sub-network of the InternetGPRS Features Cont.•Spectrum Efficiency–users can share the resource (Radio link),it is used only when users are actually sending or receiving data •Speed: Based on GMSK–a modulation technique known as Gaussian minimum-shift keying.–Theoretical Max speeds up to 171.2kbps.(GSM:9.6Kbps)GPRS Features Cont.–a channel that is 200kHz wide, is divided into 8 separate data streams, each carrying maximum 20kbps(14.4kbps typical), GSM only use one channel, GPRS combine up to 8 of these channels.•complement rather than replace the current data services available through today’s GSM–doesn't require new radio spectrum–supports TDMA: also use for IS-136GPRS Phrase•Phrase 1–expectedly to be available commercially in 2001, Point to point GPRS will be supported•Phrase 2–net yet fully defined, but is expected to higher data rates through possible incorporation of techniques such as EDGE, in addition to Point-to-Multipoint support.EDGE(Enhanced Data Rates for GSM Evolution)•Introduce new methods at the physical layer–new form of modulation: 8PSK(phrase Shift Keying)•introduced as a complement to GMSK (Gaussian Filter Minimum Shift Keying)•8PSK: use 8 phrases to carry signals–Different ways of encoding •nine MCS(Module Coding Schemes) have been defined, from 8.8kbps per timeslot(MCS-1 with GMSK modulation) up to