Mobile Network
2.5G
- 3G systems took a longer time to be developed - 4G Faster than 3G Some operators move towards 2.5G :- 1. EDGE (Enhanced Data Rate for GSM Evolution) 2. GPRS (General Packet Radio Service)
Long-Term Evolution (LTE)
- A standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA technologies -Faster speeds - Approximately 10 times faster than 3G
GSM
- Cellular system, just like AMPS - Much wider than AMPS (200 kHz compared to 30 kHz) - GSM system has 124 channels
D-AMPS
- Fully digital - Operates on a new frequency band: upstream 1850-1910MHz, downstream 1930-1990MHz - Voice signal is digitized by using PCM encoding
Call Management
- Mobile phone has a 32 bit serial number and a 10 digit telephone number - When the phone is switched on, it scans to find the most powerful signal - The phone then broadcast its serial number and its phone number - The base station records the presence of a new customer
CDMA
- Totally different with AMPS, D-AMPS and GSM - CDMA allows each station to transmit over the entire frequency spectrum all the time - Multiple simultaneous transmissions are separated using coding theory
PDC
- Was a 2G mobile telecommunications standard
Second-Generation
4 systems :- D-AMPS - Digital Advanced Mobile Phone System GSM - Global System for Mobile Communications CDMA - Code Division Multiple Access PDC - Personal Digital Cellular
First-Generation : Advanced Mobile Phone System
AMPS system uses 832 channels from 832 to 849MHz and 832 channels from 869 to 894MHz 4 categories of 832 channels :- 1. Control (base to mobile) to manage the system 2. Paging (base to mobile) to alert users to calls for them 3. Access (bidirectional) for call setup and channel assignment 4. Data (bidirectional) for voice, fax, or data
Third-Generation Wireless mobile telecommunications technology is the upgrade for 2G and 2.5G GPRS networks for faster internet speed
Basic services an IMT-2000 network :- 1. High-quality voice transmission 2. Messaging (replace e-mail, fax, SMS, chat) 3. Multimedia (music, videos, films, TV) 4. Internet access (web surfing)
Differences GSM & CDM
GSM :- - 80% market share worldwide - Required sim cards - Can be unlocked to other GSM networks CDM :- - 50% market share in US (Also popular in Asia) - Don't require sim cards - Phone itself is locked to network provider
Mobile Network
Mobile network is a communication network where the last link is wireless
Pulse Code Modulation (PCM)
Used by telephone networks for the digital transmission of analog data.
