# 2G ## Requirements ## Solutions [GSM](Global%20System%20for%20Mobile.md) [IS-95](Interim%20Standard%2095.md) Dual-band or triband Circuit switched data are charged on a per-second basis. You occupy the whole circuit the whole time. ## Major Breakthroughs 1. Smaller handset (electronics advancements) 2. Longer lifetime of handset 1. GSM - power control for prolonging battery life 3. [Gaussian Minimum Shift Keying](Gaussian%20Minimum%20Shift%20Keying.md) 4. [Channel coding](Channel%20coding.md) 5. Operators are free to choose [GSM](Global%20System%20for%20Mobile.md) and [Code division multiple access](Code%20division%20multiple%20access.md) Use GPS to synchronise base stations - issues in Hong Kong where buildings caused GPS signals to be weaker, affected performance. ## Evolution Driving Force  Demand for high quality wireless internet access Led to [2.5G](../Telecommunications/2.5G.md) [^1] # References [^1]: [TELE4652-lecture-00](../../03%20-%20University/TELE4652/Lectures/TELE4652-lecture-01.pdf)