This document compares different generations of mobile phones and systems through block diagrams. It shows the evolution from 1G analog phones using FDMA to 5G phones using LTE Advanced. Key differences include how voice and data are transmitted over radio channels (circuit switched vs packetized), increasing bandwidths enabling higher speeds, and transitioning from circuit switched to packetized voice delivery.

1. COMPARISON OF
DIFFERENT MOBILE PHONE GENERATIONS
PHONES & SYSTEMS
This document explains the different generations of mobile
telephony with simplified block diagrams.

2. 1. Figure 1 shows simplified block diagrams of the different
Generations of mobile phones – 1G, 2G, 2.5G, 3G &
3.5G, 4G, and 5G.
2. Figure 2 shows the simplified block diagrams of the
different Generations of mobile phone systems – 1G, 2G,
2.5G, 3G & 3.5, 4G, and 5G.
3. Uniform numbering has been used throughout so that the
differences may be easily perceptible.
4. The first basic difference in the different generation
phones and systems lies in the manner signals from the
phone are transported through the radio spectrum
available – FDMA, FDMA/TDMA, CDMA, LTE, and LTE
Advanced.
5. The second basic difference lies in circuit switching voice
and IP data sent alternately through a single radio
channel, and simultaneous transmission of voice and data
either using circuit switched voice and IP data through a
channel splitter, or using packetised voice sent along with
data packets in queue over the single radio channel.
6. The receiving system from the BTS (tower) onwards have
to adapt to these different types of signals received
through the radio spectrum.
7. Fig.1a shows the 1G phone block diagram and Fig. 2a
shows the 1G system block diagram.
8. Fig. 1b shows the 2G phone block diagram and Fig. 2b
shows the 2G system block diagram.
9. Fig. 1c shows the 2.5G phone block diagram and Fig. 2c
shows the 2.5G system block diagram.
10. Fig. 1d shows the 3G phone block diagram and Fig. 2d
shows the 3G system block diagram.
11. Fig. 1e shows the 3.5 and 3.9G phone block diagram and
Fig. 2e shows the 3.5 and 3.9G system block diagram.
12. Fig. 1f shows the 4G and 5G phone block diagram and
Fig. 2f shows the 4G and 5G system block diagram.

3. 13. Fig.3a shows the simplified block diagram of the
cdmaOne phone (IS 95) and Fig.3b shows the
corresponding system diagram.
14. Fig.3c shows the simplified block diagram of the
W-CDMA (CDMA 2000) and Fig.3b shows the
corresponding system diagram.
15. In the 3G, 3.5G, 3.9G, and the CDMA2000 phones
simultaneous voice and data is carried out over a
single radio channel through a channel splitter (12)
shown in the block diagrams. The voice is circuit
switched end-to-end. 3G uses FDMA/TDMA
transmission protocol over the radio spectrum. 3.5G
and 3.9G use the 3GPP LTE protocol over radio
spectrum, a scalable frequency spectrum of 1.5 MHz
to 20 MHz and supports both FDD (frequency
division duplexing) and TDD (time division duplexing)
and can produce a download speed of 100Mbps and
an upload speed of 50 Mbps with a round trip delay of
10 ms.
16. In the 4G, 5G, onward phones the voice is packetised
and aggregated with the data packets and the
combined packets are routed via the LTE Advanced
transportation across the radio frequency spectrum.
Various techniques like MIMO are used to get higher
spectral efficiency, and lower latency, to get better
performance on real time communications like voice
and video. Besides the system works with higher
bandwidth and works over a range of frequency
spectrum from 20 MHz to 100 MHz. Using 100 MHz
frequency bandwidth it is possible to achieve 5 Gbps
download to a mobile station moving at 10 Km./Hr.
17.The basic difference between 3.5G/3.9G phone and
the 4G flat IP phone is the channel splitter is replaced
by the voice Packetiser and Packet Aggregator, and
the replacement of LTE with LTE Advanced.

4. Fig. 1
SIMPLIFIED BLOCK DIAGRAMS EXPLAINING
DIFFERENT GENERATIONS OF MOBILE PHONES
1a 1
3 4 5
2a 2 15
Fig. 1a -1G (Analogue Mobile Phone)
1a 1
3 6 7 8 4 9 5 15
2a 2
Fig. 1b - 2G (Digital Mobile Phone)
1a 1
3 6 7 8 4 9
2 5 15
2a
IP
10 11
Fig. 1c - 2.5 G (GPRS)
15
1a 1
3 6 7 8 4 9
2a 2 12 5
IP
10 11
Fig. 1d – 3G
15
1a 1
3 6 7 8
2a 2 12 28 5
IP
10 11
Fig 1e - 3.5G & 3.9G
1a 1 15
IP
3 6 7 8 14
28
2a 2 13 A 5
IP
10 11
Fig 1f - 4G & 5G

5. Index
1. Ear transducer
a. Audio waves to ear
2. Mouth transducer
a. Audio waves from mouth
3. Duplexer
4. FDMA frequency allocator
5. Modulator
6. Voice codec
7. Channel coder
8. Interleaving device (convolution coding)
9. TDMA time slice allocator
10. Mobile phone data application or Laptop
11. Packetiser for digital data
12. Channel splitter (multiplexer)
13. Packet aggregator
14. Digital voice Packetiser
15. Radio spectrum
16. BTS Tower
17. BSC – Digital PCM TDM switch for base station
18. Codec for each analogue signal from FDMA at BTS
19. Digital trunks for connecting to MSC.
20. MSC – Digital PCM TDM master switching station of
MSP (mobile service provider)
21. IP Backbone of MSP / TSP
22. Internet interconnected with MSP IP Backbone
23. IP Trunk card in BSC, MSC, and LEX of PSTN which
has the packetising / de-packetising capability and link
the VoIP telephony with Circuit Switched telephony.
24. Note that the MSC supports the entire circuit switched
mobile network of the MSP from 2G to 3.5G, whereas
the 4G, 5G onwards as planned will route packet voice
through the IP Backbone and connects to MSC through
IP Trunk cards.

6. 25. Base Station Building containing Packet aggregator,
Data Packetiser, Voice Packetiser, and connection to
POP of IP Backbone
26. LEX (local exchange) of PSTN .
27. CDMA multiplexer
28. LTE
28A. LTE Advanced

7. Fig 2
SIMPLIFIED BLOCK DIAGRAM OF
SYSTEM CONFIGURATION OF
DIFFERENT MOBIL PHONE GENERATIONS
FDMA
P
1 1 TDM TDM
16 5 4 S
Ana CS 8 17 9 20
T
FDMA
N
1 TDM
5 4 1
16
FDMA
Ana CS 8 17 9
Fig.2a -1G (Analogue Mobile Phone) System
TDMA / FDMA Digi CS
TDM P
9 6 1 1 TDM
16 5 4
8 17 9
S
20
8 7 T
TDMA / FDMA N
Digi CS
TDM
9 6 1 1
16 5 4
8 17 9
8 7
Fig 2b - 2G (Digital Mobile Phone) System
TDMA / FDMA Digi CS
8 7 P
1 TDM TDM
16 9 6 1 S
5 4 8 17 9 20
T
IP N
TDM
Digi CS
TDMA / FDMA
8 7
5 9 6 1 1
16 4 8 17 9 21
IP
22
Fig 2c - 2.5G (GPRS) System

8. Fig 2 (Contd.)
3G – FDMA/TDMA
3.5G/3.9G - LTE
8 7
16 9 6 1 1
1 4
5 2 8 17 9 20 26
23 23
2
8
3G – FDMA/TDMA
3.5G/3.9G - LTE
8 7
9 6 1 1 21
5 1 4 TDM / SDH
16 2 8 17 9
TRANSPORT
NETWORK
2
8
22
Fig 2d / e - 3G & 3.5G/3.9G(Simultaneous Voice & Data Communication) System
With Circuit Switched Voice and Packet Switched Data Communications
The difference between 3G and 3.5G/3.9G is only in the transport protocol through radio
spectrum and bandwidth
LTE Adv
24
2
16 5 8 13
17 20
A 26
23
23 23
LTE Adv
24
2
16 5 1 17
8
3 21
A 23
TDM/SDH
TRANSPORT
NETWORK
22
Fig 2f - 4G & 5G(Simultaneous Voice & Data Communication) System
With Packet Switched Voice and Packet Switched Data Communications
Interconnects with BSC, MSC, PSTN through IP Trunks

9. Fig 3
CDMA PHONE & SYSTEM
1a 1
3 6 7 8 27
2a 2 5 15
10 11
Fig. 3a - 2.5 G cdmaOne (IS95)PHONE
CDMA
P
8 7
16 6 1 1 S
5 27 17 20
8 9 T
N
CDMA
16
8 7 1
6 1
5 27 8 17 9 21
Fig.3b - 2.5G cdmaOne (IS95)System 22
1a 1
1
3 6 7 8 2 27
2a 2 5 15
10 11
Fig.3c – W-CDMA (CDMA2000)PHONE
CDMA
8 7
16 1 6 1
5 27 17
2 9 20 26
23 23
CDMA
8 7
16 6 1 21 TDM / SDH
5 27 1 17
2 9 TRANSPORT
NETWORK
22
Fig.3d – W-CDMA (CDMA2000) System