Cellular Network Standards

Question 1

Cellular networks

Answer 1

• Mobile devices - “Cell” phones
  
  • Separate land into “cells”
  • Antenna coverages a cell with certain frequencies
• 2G networks
  
  • GSM - Global System for Mobile Communications
  • CDMA - Code Division Multiple Access
• Poor data support
  
  • Originally used circuit-switching
  • Minor upgrades for some packet-switching

Question 2

GSM

Answer 2

• Global System for Mobile Communications
  
  • Mobile networking standard
• 90% of the market
  
  • Originally an EU standard - Worldwide coverage

• Used by AT&T and T-Mobile in the United States
• Move your SIM card (Subscriber Identity Module)
from phone to phone

• Original GSM standard uses TDMA to multiplex calls
  
  • Everyone gets a little slice of time

Question 3

Time-Division Multiple Access (TDMA)

Answer 3

• Multiple streams are combined into a single stream, and then broken out again - “Muxing”

Question 4

CDMA

Answer 4

• Code Division Multiple Access
• Everyone communicates at the same time
• Each call uses a different code
• The codes are used to filter each call on the
receiving side

• Used by Verizon and Sprint
  
  • Handsets are controlled by the network provider
  • Not much adoption elsewhere

Question 5

4G and LTE

Answer 5

• Long Term Evolution (LTE) - A “4G” technology
• Converged standard (GSM and CDMA providers)
• Based on GSM and EDGE (Enhanced Data Rates for
GSM Evolution
• Standard supports download rates of 150 Mbit/s

• LTE Advanced (LTE-A)
  
  • Standard supports download rates of 300 Mbit/s