Cellular Networks
- Mobile carriers are an extension of the PSTN
- Public Switch Telephone Network
- Why don't we take this service and expand it onto the air
- "1G" was launched by NTT in Japan, 1979
- The network operator maintains a mesh for coverage
- Seamless connectivity as you move
- Service areas are referred to as "cells"
- Radio frequencies vary by provider and generation
- Different towers leased off by different providers
- If I know the direction of a tower I can use a Yaggi and connect to it.
Cells
- Single radio service area
- Many frequencies
- With different generations of phones we have multiple receivers
- Different frequencies than neighboring cells
- Stays the same with wireless networks as well
- Support wide areas when grouped
- Pattern is defined by terrain
- 1G was actually clear text
2G
- Global System for Mobile Communications (GSM)
- First digital mobile network
- Developed 1991
- Digitally encrypted *
- SMS / Data services
- higher user capacity
- 2.75G = Enhanced Date Rate for GSM Evolution (EDGE)
- Fallback mechanism used globally
3G
- Universal Mobile Telecommunications System (UMTS)
- AKA CDMA2000
- Various EDGE implementations found here
- Minimum rate of 144 kbps
- Maximum rate of 56 Mbps
- Speeds will vary based on hardware and software capabilities
- Verizon, T-mobile, and AT&T are decommissioning 3G
- EV-DO (Evolution-Data Optimized) is a 3G standard used for CDMA cellular networks and can support up to 3.1 Mbps downloads.
- HSPA+ (Evolved High-Speed Packet Access) is a 3G standard used for GSM cellular networks and can support up to 168 Mbps downloads.
4G Long Term Evolution (LTE)
- IP Packet Switching is a base requirement
- 100 Mbps down / 50 up
- Smooth roaming
- Attach and detach from different cell towers smoothly
- Quality of Service
- Mark the frames of your messages as something being more important that other thing.
- WI-MAX, WI-MAX 2
- Evolved High Speed Packet Access (HSPA+)
5G
- Introduced 2016, globally deployed 2019
- Speeds of up to 10's of Gbps
- IoT / M2M applications
- ATM machines, cook machines, car washes, and all sorts of equipments.
- Many more machines on the network than previously
- Three bands in use
- Low 600-800hz, 30-250 Mbps
- Med 2.5-3.7 Ghz, 100-900 Mbps
- High 25-39 Ghz, 10's of Gbps
- The lower frequencies go further but are slower, the high frequencies go very fast but they have limited reachability
6G
- Speeds of 95 Gbps
- Target arrival 2030s
- Researchers working in 100's of Ghz frequency range
- Thz on the horizon
- China launched an experimental 6G satellite in late November 2020