Moving to 3G faster and higher quality networks started supporting better services like video calling, video streaming, mobile gaming and fast Internet browsing, it resulted in the introduction of the 3rd generation mobile telecommunication standard (UMTS). 3G network were developed to offer high speed data and multimedia connectivity to subscribers

Evolution of cellular technologies

3G Overview 3G is created by ITU-T and is called IMT-2000 IMT-2000, “International Mobile Telecommunications” IMT-2000, “International Mobile Telecommunications” Wideband Code Division Multiple Access CDMA Code Division Multiple Access 2000 UMTS - Universal Mobile Telecommunications System time division duplex- code division multiple access Time Division Synchronous Code Division Multiple Access Universal Wireless Communications Digital Enhanced Cordless Telecommunications

Service Roadmap Improved performance, decreasing cost of delivery Typical average bit rates (peak rates higher) WEB browsing Corporate data access Streaming audio/video Voice & SMS Presence/location xHTML browsing Application downloading MMS picture / video Multitasking 3G-specific services take advantage of higher bandwidth and/or real-time QoS A number of mobile services are bearer independent in nature HSDPA 1-10 Mbps WCDMA 2 Mbps EGPRS 473 kbps GPRS 171 kbps GSM 9.6 kbps Push-to-talk Broadband in wide area Video sharing Video telephony Real-time IP multimedia and games Multicasting

GSM Evolution to 3G GSM 9.6kbps (one timeslot) GSM Data Also called CSD GSM General Packet Radio Services Data rates up to ~ 115 kbps Max: 8 timeslots used as any one time Packet switched; resources not tied up all the time Contention based. Efficient, but variable delays GSM / GPRS core network re-used by WCDMA (3G) GPRS HSCSD High Speed Circuit Switched Data Dedicate up to 4 timeslots for data connection ~ 50 kbps Good for real-time applications c.w. GPRS Inefficient -> ties up resources, even when nothing sent Not as popular as GPRS (many skipping HSCSD) EDGE Enhanced Data Rates for Global Evolution mprovement in data rate on short distances Can fall back to GMSK for greater distances Combine with GPRS (EGPRS) ~ 384 kbps Can also be combined with HSCSD WCDMA

UMTS Universal Mobile Telecommunications System (UMTS) UMTS is an upgrade from GSM via GPRS or EDGE The standardization work for UMTS is carried out by Third Generation Partnership Project (3GPP) Data rates of UMTS are: – 144 kbps for rural – 384 kbps for urban outdoor – 2048 kbps for indoor and low range outdoor

UMTS Frequency Spectrum UMTS Band – MHz and MHz for 3G transmission – In the US, 1710–1755 MHz and 2110–2155 MHz will be used instead, as the 1900 MHz band was already used.

UMTS Architecture

Gateway GPRS support node (GGSN)[ Gateway GPRS support node (GGSN) The gateway GPRS support node (GGSN) is a main component of the GPRS network. The GGSN is responsible for the internetworking between the GPRS network and external packet switched networks, like the InternetInternet From an external network's point of view, the GGSN is a router to a "sub-network", because the GGSN ‘hides’ the GPRS infrastructure from the external network.

Gateway GPRS support node (GGSN)[ When the GGSN receives data addressed to a specific user, it checks if the user is active. 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. On the other hand, mobile-originated packets are routed to the right network by the GGSN. The GGSN is the anchor point that enables the mobility of the user terminal in the GPRS/UMTS networksUMTS

Gateway GPRS support node (GGSN)[ The GGSN converts the GPRS packets coming from the SGSN into the appropriate packet data protocol (PDP) format (e.g., IP or X.25) and sends them out on the corresponding packet data network

Serving GPRS support node (SGSN) A serving GPRS support node (SGSN) is responsible for the delivery of data packets from and to the mobile stations within its geographical service area. Its tasks include packet routing and transfer, mobility management (attach/detach and location management), authentication and charging functions. The location register of the SGSN stores location information.

UMTS Network Architecture UMTS network architecture consists of three domains – Core Network (CN): Provide switching, routing and transit for user traffic – UMTS Terrestrial Radio Access Network (UTRAN): Provides the air interface access method for user equipment. – User Equipment (UE): Terminals work as air interface counterpart for base stations. The various identities are: IMSI, TMSI, P-TMSI, TLLI, MSISDN, IMEI, IMEISV

UTRAN Wide band CDMA technology is selected for UTRAN air interface Base stations are referred to as Node-B and control equipment for Node-B is called as Radio Network Controller (RNC). – Functions of Node-B are Air Interface Tx/Rx Modulation/Demodulation – Functions of RNC are: Radio Resource Control Channel Allocation Power Control Settings Handover Control Ciphering Segmentation and reassembly

3.5G (HSPA) High Speed Packet Access (HSPA) is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), that extends and improves the performance of existing WCDMA protocolsWCDMA 3.5G introduces many new features that will enhance the UMTS technology in future.

4G (LTE) LTE stands for Long Term Evolution Next Generation mobile broadband technology Promises data transfer rates of 100 Mbps Based on UMTS 3G technology Optimized for All-IP traffic

LTE

Background of LTE key requirements was defined for the new system Packet-switched domain optimization Roundtrip time between server and user equipment (UE) must be bellow 30ms and access delay below 300 ms Uplink peak rate 75 Mbps Downlink peak rate 300Mbps Improvements to mobility and security Terminal power efficiency improvements Capacity increase compared to 3GPP release 6 (HSDPA/HSUPA

Comparison of LTE Speed

HSPA vs LTE

Advantages of LTE

Major LTE Radio Technogies Uses Orthogonal Frequency Division Multiplexing (OFDM) for downlink Uses Single Carrier Frequency Division Multiple Access (SC-FDMA) for uplink Uses Multi-input Multi-output(MIMO) for enhanced throughput Reduced power consumption

OFDMA & SC-FDMA The LTE air interface uses Orthogonal Frequency Division Multiplexing (OFDM). Also to reach the agreed data levels multiple input / multiple output (MIMO) technologies, together with high rate modulation OFDMA is used in the downlink of LTE but for the uplink Single Carrier – Frequency Division Multiple Access (SC-FDMA) OFDM-based technology was chosen for the following reason – it can achieve the targeted high data rates with simpler implementations involving relatively low cost and power- efficient hardware

multiple input / multiple output (MIMO) To minimize the effects of noise and to increase the spectrum utilization and link reliability LTE uses MIMO technique to send the data. The basic idea of MIMO is to use multiple antennas at receiver end and use multiple transmitters when sending the data

LTE impact on network architecture The LTE network architecture is an overall flat architecture It consists of an e-Node B and SAE gateway. This network is based on a TCP/IP protocol with higher service levels like voice, video, messaging, etc. built on it. Based on this, feasibility studies related to All IP networks (AIPNs) were started in 2004 by the 3GPP

LTE Architecture

LTE vs UMTS Functional changes compared to the current UMTS architecture

LTE Release 8 Key Features (1/2) High spectral efficiency – OFDM in Downlink – Single‐Carrier FDMA in Uplink Very low latency – Short setup time & Short transfer delay – Short hand over latency and interruption time Support of variable bandwidth – 1.4, 3, 5, 10, 15 and 20 MHz 28

LTE Release 8 Key Features (2/2) Compatibility and interworking with earlier 3G PP Releases FDD and TDD within a single radio access tech nology Efficient Multicast/Broadcast 29

Evolution of LTE-Advanced (4G) Advanced Multi-cell Transmission/Reception Techniques Enhanced Multi-antenna Transmission Techniques Support of Larger Bandwidth in LTE-Advanced 30

LTE-Advanced (4G) Peak data rates up to 1Gbps are expected from bandwidths of 100MHz. OFDM adds additional sub-carrier to increase bandwidth 31

LTE vs. LTE-Advanced 32

Conclusion LTE-A helps in integrating the existing networks, new networks, services and terminals to suit the escalating user demands LTE-Advanced will be standardized in the 3GPP specification Release 10 (LTE-A) and will be designed to meet the 4G requirements as defined by ITU 33