Cellular Networks Presented by: Ashok Kumar J Supervised by: Tamer Nadeem CS 752/852 Wireless and Mobile Networking Introducing 4G • • • • • What is 4G? Why is 4G so popular? Is 4G going to be the next world standard? How fast is 4G growing? Who currently uses 4G? US wireless carriers AT&T, Sprint, T-Mobile and Verizon are already using 4G Discussion Topics 1G 1G – First Generation Telecommunication System 2G 2G – Second Generation Telecommunication System 3G 4G Differences LTE No data transmission at all Limited data transmission which increased in 2.5G 3G – Third Generation Telecommunication System Fairly High data transmission speeds 4G – Fourth Generation Telecommunication System Completely out of the group 4G Underlying Technologies Different implementations of 4G by different constituents LTE and WiMAX LTE is being preferred over WIMAX 1G – First Generation Mobile Telecommunication • • • • • • Analog Telecommunication Standard FDMA – Transmission Technique Hand-off and frequency reuse No data transmission only voice transmission First commercially automated cellular network in 1979 Standards: AMPS, NMT, TACS, JTACS, C-450, Radiocom 2000 and RMTI Drawbacks • • • Poor security due to lack of encryption Many different standards being used in different places Limitation on the number of calls that could be made simultaneously 2G – Second Generation Mobile Telecommunication • • • • • • • • Purely digital technology TDMA, GSM, CDMA – operator technologies Conversations were digitally encrypted Introduced data services for mobile, starting with SMS Commercially launched on the GSM standard in Finland in 1991 Circuit-switched data services (HSCSD) Greatly reduced fraud and discouraged cloned handsets Operates from 800/900 or 1800/1900 MHz and bandwidth of 2G is 30-200 KHz Drawbacks • • • Weak digital signal may not be sufficient especially in higher frequencies Increased dropouts Very slow data transmission 2G Transitional – 2.5G, 2.75G 2.5G Packet-switched domain in addition to the circuit-switched domain GPRS: The first major step in the evolution of GSM networks to 3G GPRS provides data rates of 56-114 kbps CDMA used CDMA2000 1XRTT CDMA data speeds of up to peak 153 kbps and generally up to 60–100 kbps GPRS Allows 2G and 3G mobile networks to transmit IP packets to the Internet Integrated part of the GSM network switching subsystem GPRS core network in GSM and WCDMA provides • Mobility management • Session management • Transport for Internet Protocol packet services • Billing based on volume of data and lawful interception 2.75G EDGE (has many versions) Standardized by 3GPP as part of the GSM family Easy upgrade to GPRS and is backward compatible Pre-3G radio technology and is part of ITU's 3G definition Can be used for any packet switched application, like Internet connection Throughput up to 236.8kbps for 4 timeslots, 473.6kbps for 8 Widely used (441 GSM/EDGE networks in 184 countries) Updates are still being released (latest version of EDGE… almost 3G) 3G – Third Generation Mobile Telecommunication • • • • • • • • Digital broadband packet access UTMS(WCDMA), CDMA2000 1xEV-DO – operator technologies Voice telephone, mobile Internet, video calls and mobile TV in a mobile. Offers greater security than 2G Supports up to 3.1mbps peak but general speed is 500-700kbps 3G was relatively slow to be adopted globally Uses different frequency spectrum than 2G Operates at 2100MHz and bandwidth of 15-20MHz Drawbacks • • • • No proper backward compatibility Need to replace most broadcast towers No formal definition – carriers used their own technologies to implement 3G network Expensive Construction and maintenance 3G Transitional – 3.5G, 3.75G, 3.9G HSPA(has many versions) Amalgamation of two mobile telephony protocols Improves the performance of existing UTMS protocols Fairly high peak data downlink rates up to 3.6/ 7.2/ 14.4 mbps Fairly high peak data uplink rates up to 5.76mbps General speeds are in between 1-3mbps Reducing the production cost per bit Over 200 operator in more than 80 countries Easy update to existing 3G networks. Preferred over WiMAX, which requires a dedicated network infrastructure Comparison of Generations 1G, 2G, 3G, 4G. Generation Definition Throughput Technologies 1G Analog 14.4 kbps (peak) AMPS,NMT,TACS 2G Digital 9.6/14.4 kbps(peak) TDMA, GSM, CDMA (Narrow band Circuit Data) 2G Transitional Packet Data 114/236.8 kbps(peak) 20-40 kbps HSCSD, GPRS, EDGE 3G Digital broadband packet data 3.1 mbps (peak) 500-700 kbps UTMS, CDMA2000 1XRTT 3G Transitional >2mbps 3.6/7.2/14.4 mbps(peak) 1-3 mbps HSPA, CDMA2000 EV-DO 4G Digital broadband packet based 100 – 300 mbps (peak) 3-12 mbps LTE Advanced WiMax Advanced HSPA+ All IP (VOIP) 4G – Fourth Generation Mobile Telecommunication • • • • • • • • • All IP based secured packet switched network Voice also transmitted over IP Supports IPv6 Access schemes – OFDMA, SC-FDMA, MC-CDMA Supports up to 100mbps downlink and 50mbps uplink. Using MIMO, speed can be increased. Technologies – LTE, WiMAX, Wi-Fi metro, HSPA+. No formal specification – Operators making their own choices. Verizon, Sprint, ATT, T-Mobile are offering. 4G (Continued) Ressource: http://4gwirelessjobs.com/lte_wimax.htm 4G (Continued) Ressource: http://4gwirelessjobs.com/lte_wimax.htm 4G Technologies LTE Advanced (E-UTRAN) • • • • • • WiMAX Advanced Proposed by 3GPP based on UMTS/HSPA. OFDMA for uplink and downlink • Proposed by IEEE based on WiMAX • Can be constructed using existing 3G network. Backward compatible. Downlink up to 100mbps and uplink up to 50mbps. Natural upgrade to GSM/UMTS networks, can be using by CDMA networks also. • OFDMA for downlink and SC-FDMA for uplink. Requires completely different network. Backward compatible. Bit rates up to 40mbps. Can be used by any network. • • • Resource: www.itechdiary.com/compared-wimax-versus-lte4g.html Resource: http://1001-tricks.blogspot.com/2010/12/lifehacker-explains-4g-technology.html Long Term Evolution - Advanced • • • • • • Increased downlink and uplink peak data rates. Scalable bandwidth and flexible bandwidth. Improved spectral efficiency All IP network A standard’s based interface that can support a multitude of user types. LTE networks are intended to bridge the functional data exchange gap between very high data rate fixed wireless Local Area Networks (LAN) and very high mobility cellular networks. Questions?