Cellular Wireless Networks Chapter 10

Cellular Network Organization Use multiple low-power transmitters (100 W or less) Areas divided into cells Each served by its own antenna Served by base station consisting of transmitter, receiver, and control unit Band of frequencies allocated Cells set up such that antennas of all neighbors are equidistant (hexagonal pattern)

Cellular Network Organization hexagonal pattern

Frequency Reuse Adjacent cells assigned different frequencies to avoid interference or crosstalk Objective is to reuse frequency in nearby cells 10 to 50 frequencies assigned to each cell Transmission power controlled to limit power at that frequency escaping to adjacent cells The issue is to determine how many cells must intervene between two cells using the same frequency

WWAN Technologies GSM (Global System for Mobile Communications) GPRS (General Packet Radio Service) EDGE (Enhanced Data Rate for GSM Evolution) UMTS (Universal Mobile Telecommunications System) HSPA (High Speed Packet Access) LTE (Long Term Evolution) Evolution of Mobile technology: 0G, 1G, 2G, 3G, & 4G

WWAN Technologies GSM (Global System for Mobile Communications) GSM is an international standard Its started since 1991, (2 G). It uses digital systems It uses TDMA as access method GSM operates in 900 MHz band (890 MHz - 960 MHz) in Europe and Asia and 1.9 GHz in US. GSM Data rate is 9.6 ~ 14.4 Kbps.

WWAN Technologies GSM Features: GSM uses encryption Instant Messaging SMS (Short Message Service) Data Networking

WWAN Technologies GPRS (General Packet Radio Service) GPRS is an alternative to circuit-switched voice connection (2.5 G, since 2000+) GPRS uses Internet Protocol Its used in smartphones GPRS “always-on” connection. GPRS Data rate is 114 Kbps.

WWAN Technologies GPRS Features: Allows smartphones to run applications remotely over a network Interface with the internet Act as a wireless modem for a computer Transmit and receive E-mails Send and receive data

WWAN Technologies EDGE (Enhanced Data Rate for GSM Evolution) EDGE is a digital technology based on GSM technology (2.75 G), since 2003. Mobile Phones should support EDGE technology EDGE technology available in more than 170 countries all over the world. EDGE Data rate is 474 Kbps.

WWAN Technologies EDGE Features: More wireless data applications Wireless Multimedia Web E-mails Video conferencing

WWAN Technologies UMTS (Universal Mobile Telecommunications System) UMTS is a voice and high-speed data technology (3G) based on GSM technology. WCDMA (Wideband-CDMA) & UMTS are used interchangeably. UMTS based on Internet Protocol (IP) . UMTS Data rate is 384 Kbps (original release).

WWAN Technologies UMTS Features: Global Mobile-Broadband Network. It is more mature and benefits from research and development. Commercially deployed. High spectral efficiency for voice and data. Support for high-bandwidth data applications.

WWAN Technologies HSPA (High Speed Packet Access) HSPA is a terminology used when both HSDPA (High Speed Downlink Packet Access and HSUPA (High Speed Uplink Packet Access) are deployed in a network. Speed 14 Mbps on downlink & 5.8 Mbps on uplink in a 5Mhz channel.

WWAN Technologies HSPA+: (Evolved HSPA) Speed is 21 Mbps. LTE: (Long Term Evolution) Speed is ??? Mbps.

WWAN Technologies LTE – Long Term Evolution: It is 4G Technology, since 2009. It is based on GSM/EDGE and UMTS/HSPA Technologies. Its main objective is to increase the capacity and speed of wireless data networks. LTE Specifications (300 Mbps for downlink and 75 Mbps for uplink).