1. 2143404 MULTIMEDIA ENGINEERING ISE (International School of Engineering, CU) Information and Communication Engineering 4 2.5G Mobile Phone and Network By Peeravat Kumpeera 5031360421 Mobile Device

2. 1.2.5G is 2.2.5G is INTRODUCTION ISE (International School of Engineering, CU) Information and Communication Engineering 4 A technology between the second (2G) and third (3G) generations of mobile telephony Sometimes described as 2G cellular technology combined with GPRS

3. ISE (International School of Engineering, CU) Information and Communication Engineering 4 In 2G systems, GPRS provides data rates of 56-114 kb/s.

4. ISE (International School of Engineering, CU) Information and Communication Engineering 4 a best-effort service, as opposed to circuit switching, where a certain quality of service (QoS) is guaranteed during the connection

5. ISE (International School of Engineering, CU) Information and Communication Engineering 4 Usage charging is based on volume of data, either as part of a bundle or on a pay as you use basis.

6. Services Offered by 2.5G Technology GPRS extends the GSM circuit switched data capabilities and makes the following services possible : 1.Always on" internet access 2.Multimedia messaging service (MMS) 3.Push to talk over cellular (PoC/PTT) 4.Instant messaging and presence—wireless village 5.Internet applications for smart devices through wireless application protocol (WAP) 6.Point-to-point (P2P) service: inter-networking with the Internet (IP) ISE (International School of Engineering, CU) Information and Communication Engineering 4

7. Hardware Devices supporting GPRS are divided into three classes: Class A - GPRS and GSM both at the same time Class B - GPRS and GSM one at a time Class C - GPRS and GSM one at a time, switches manually ISE (International School of Engineering, CU) Information and Communication Engineering 4

8. ISE (International School of Engineering, CU) Information and Communication Engineering 4 Addressing A GPRS connection is established by reference to its access point name (APN). The APN defines the services such as wireless application protocol (WAP) access, short message service (SMS), multimedia messaging service (MMS), and for Internet communication services Eg. email and World Wide Web access. In order to set up a GPRS connection for a wireless modem, a user must specify an APN, optionally a user name and password, and very rarely an IP address, all provided by the network operator.

9. Coding Schemes & Speed The upload and download speeds that can be achieved in GPRS depend on a number of factors such as: 1.The number of base transceiver station (BTS) TDMA time slots assigned by the operator 2.The channel encoding used 3.The maximum capability of the mobile device expressed as a GPRS multislot class ISE (International School of Engineering, CU) Information and Communication Engineering 4

10. Usability ISE (International School of Engineering, CU) Information and Communication Engineering 4  The maximum speed of a GPRS connection offered in 2003 was similar to a modem connection in an analog wire telephone network, about 32-40 kbit/s  Latency is very high; round-trip time (RTT) is typically about 600-700 ms and often reaches 1 s.  GPRS is typically prioritized lower than speech, and thus the quality of connection varies greatly.

11. Usability ISE (International School of Engineering, CU) Information and Communication Engineering 4 Devices with latency/RTT improvements are generally available. Also, network upgrades of features are available with certain operators. With these enhancements the active round-trip time can be reduced, resulting in significant increase in application-level throughput speeds.

12. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4

13. GPRS Core Network  The GPRS core network is the centralized part of the General Packet Radio Service (GPRS) system for 2G and WCDMA based 3G mobile networks.  The GPRS system is used for transmitting IP packets and the GPRS core network is an integrated part of the GSM network switching subsystem. ISE (International School of Engineering, CU) Information and Communication Engineering 4

14. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 General Support Functions : 1.The GPRS core network provides mobility management, session management and transport for Internet Protocol packet services in GSM and WCDMA networks. 2.The core network also provides support for other additional functions such as billing and lawful interception. 3.It was also proposed, at one stage, to support packet radio services in the US D-AMPS TDMA system, however, in practice, all of these networks have been converted to GSM so this option has become irrelevant.

15. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 GPRS Tunneling Protocol (GTP) : GPRS tunneling protocol is the defining IP protocol of the GPRS core network. Primarily it is the protocol which allows end users of a GSM or WCDMA network to move from place to place while continuing to connect to the Internet as if from one location at the Gateway GPRS Support Node (GGSN). It does this by carrying the subscriber's data from the subscriber's current Serving GPRS Support Node (SGSN) to the GGSN which is handling the subscriber's session. Three forms of GTP are used by the GPRS core network. 1.GTP-U : for transfer of user data in separated tunnels for each Packet Data Protocol (PDP) context 2.GTP-C : 3.GTP’ : for transfer of charging data from GSNs to the charging function. for control reasons including: a)setup and deletion of PDP contexts b)verification of GSN reachability c)updates; e.g., as subscribers move from one SGSN to another.

16. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 GPRS Supporting Nodes (GSN) : A GSN is a network node which supports the use of GPRS in the GSM core network. All GSNs should have a Gn interface and support the GPRS tunnelling protocol. There are two key variants of the GSN, namely… 1. Gateway GPRS Support Node (GGSN) 2. Serving GRPS Support Node (SGSN)

17. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 Gateway GPRS Support Node (GGSN) The main component of the GPRS network Responsible for the interworking between the GPRS network and external packet switched networks

18. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 Gateway GPRS Support Node (GGSN) 1.When the GGSN receives data addressed to a specific user, it checks if the user is active. 2.If it is, the GGSN forwards the data to the SGSN serving the mobile user, but if the mobile user is inactive, the data is discarded. 3.On the other hand, mobile-originated packets are routed to the right network by the GGSN. Common GGSN Functions :

19. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 Serving GPRS Support Node (SGSN) Responsible for the delivery of data packets from and to the mobile stations within its geographical service area Packet routing and transfer Mobility management Logical link management, and authentication and charging functions. The location register of the SGSN stores location information and user profiles of all GPRS users registered with this SGSN

20. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 Serving GPRS Support Node (SGSN) Common SGSN Functions : 1.Detunnel GTP packets from the GGSN (downlink) 2.Tunnel IP packets toward the GGSN (uplink) 3.Carry out mobility management as Standby mode mobile moves from one Routing Area to another Routing Area 4.Billing user data

21. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 Serving GPRS Support Node (SGSN) GSM/EDGE SPECIFIC SGSN Functions : 1.Maximum data rate of approx. 60 kbit/s (150 kbit/s for EDGE) per subscriber 2.Connect via frame relay or IP to the Packet Control Unit using the Gb protocol stack 3.Accept uplink data to form IP packets 4.Encrypt down-link data, decrypt up-link data 5.Carry out mobility management to the level of a cell for connected mode mobiles

22. GPRS Core Network ISE (International School of Engineering, CU) Information and Communication Engineering 4 Serving GPRS Support Node (SGSN) WCDMA SPECIFIC SGSN Functions : 1.Carry up to about 42 Mbit/s traffic downlink and 5.8 Mbit/s traffic uplink (HSPA+) 2.Tunnel/detunnel downlink/uplink packets toward the radio network controller (RNC) 3.Carry out mobility management to the level of an RNC for connected mode mobiles

23. ISE (International School of Engineering, CU) Information and Communication Engineering 4 Thank you for participating.