A comparison of mobile phone standards can be done in many ways.
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Global System for Mobile Communications (GSM, around 80–85 % market share) and IS-95 (around 10–15 % market share) were the two most prevalent 2G mobile communication technologies in 2007.[1] In 3G, the most prevalent technology was UMTS with CDMA-2000 in close contention.
All radio access technologies have to solve the same problems: to divide the finite RF spectrum among multiple users as efficiently as possible. GSM uses TDMA and FDMA for user and cell separation. UMTS, IS-95 and CDMA-2000 use CDMA. WIMAX and LTE use OFDM.
In theory, CDMA, TDMA and FDMA have exactly the same spectral efficiency but practically, each has its own challenges – power control in the case of CDMA, timing in the case of TDMA, and frequency generation/filtering in the case of FDMA.
For a classic example for understanding the fundamental difference of TDMA and CDMA imagine a cocktail party, where couples are talking to each other in a single room. The room represents the available bandwidth:
Feature | NMT | GSM | UMTS (3GSM) | IS-95 (CDMA one) | IS-2000 (CDMA 2000) |
---|---|---|---|---|---|
Technology | FDMA | TDMA and FDMA | W-CDMA | CDMA | CDMA |
Generation | 1G | 2G | 3G | 2G | 3G |
Encoding | Analog | Digital | Digital | Digital | Digital |
Year of First Use | 1981 | 1991 | 2001 | 1995 | 2000 / 2002 |
Global market share | 0% | 72% | 12% | 0.6% | 12% |
Roaming | Nordics and several other European countries | Worldwide, all countries except Japan and South Korea | Worldwide | Limited | Limited |
Handset interoperability | None | SIM card | SIM card | None | RUIM (rarely used) |
Operator locking | Monopoly | Unlockable | Unlockable | ESN | ESN |
Common Interference | None | Some electronics, e.g. amplifiers | None | None | None |
Signal quality/coverage area | Good coverage due to low frequencies | Good coverage indoors on 850/900 MHz. Repeaters possible. 35 km hard limit. | Smaller cells and lower indoors coverage on 2100 MHz; equivalent coverage indoors and superior range to GSM on 850/900 MHz. | Unlimited cell size, low transmitter power permits large cells | Unlimited cell size, low transmitter power permits large cells |
Frequency utilization/Call density | Very low density | 0.2 MHz = 8 timeslots. Each timeslot can hold up to 2 calls (4 calls with VAMOS) through interleaving. | 5 MHz = 2 Mbit/s. 42Mbit/s for HSPA+. Each call uses 1.8-12 kbit/s depending on chosen quality and audio complexity. | Lower than CDMA-2000? | 1.228 MHz = 3Mbit/s |
Battery life | Low, due to high transmitter power (1 watt) | Very good due to simple protocol, good coverage and mature, power-efficient chipsets. | Originally lower than GSM, but with new chipsets, DTX/DRX and Voice over HSPA all improve battery life close to that of GSM. | Lower due to high demands of CDMA power control. | Lower due to high demands of CDMA power control and young chipsets. |
Handoff | Hard | Hard | Soft | Soft | Soft |
Cell Breathing | No | No | Yes | Yes | Yes |
Voice and Data at the same time | No | Yes GPRS Class A | Yes[2] | No | Yes SVDO[3] |
Intellectual property | Scandinavian telecom operators | Concentrated among a few manufacturers | Concentrated among a few manufacturers | Qualcomm | Qualcomm |
This graphic compares the market shares of the different mobile standards.
In a fast growing market, GSM/3GSM (red) grows faster than the market and is gaining market share, the CDMA family (blue) grows at about the same rate as the market, while other technologies (grey) are being phased out.
As a reference, a comparison of mobile and non-mobile wireless Internet standards follows.
Common Name |
Family | Primary Use | Radio Tech | Downstream (Mbit/s) |
Upstream (Mbit/s) |
Notes |
---|---|---|---|---|---|---|
HSPA+ | 3GPP | Used in 4G | CDMA/FDD MIMO |
21 42 84 672 |
5.8 11.5 22 168 |
HSPA+ is widely deployed. Revision 11 of the 3GPP states that HSPA+ is expected to have a throughput capacity of 672 Mbps. |
LTE | 3GPP | General 4G | OFDMA/MIMO/SC-FDMA | 100 Cat3 150 Cat4 300 Cat5 (in 20 MHz FDD) [8] |
50 Cat3/4 75 Cat5 (in 20 MHz FDD)[8] |
LTE-Advanced update expected to offer peak rates up to 1 Gbit/s fixed speeds and 100 Mb/s to mobile users. |
WiMAX | 802.16 | Mobile Internet cf. 802.16e | MIMO-SOFDMA | 128 (in 20 MHz bandwidth FDD) | 56 (in 20 MHz bandwidth FDD) | WiMAX update IEEE 802.16m is to offer peak rates of at least 1 Gbit/s fixed speeds and 100 Mbit/s to mobile users.[9] |
Flash-OFDM | Flash-OFDM | Mobile Internet mobility up to 200 mph (350 km/h) |
Flash-OFDM | 5.3 10.6 15.9 |
1.8 3.6 5.4 |
Mobile range 30 km (18 miles) extended range 55 km (34 miles) |
HIPERMAN | HIPERMAN | Mobile Internet | OFDM | 56.9 | ||
Wi-Fi | 802.11 (11n) |
Mobile Internet | OFDM/MIMO | 300 (using 4x4 configuration in 20 MHz bandwidth) or 600 (using 4x4 configuration in 40 MHz bandwidth) |
Antenna, RF front end enhancements and minor protocol timer tweaks have helped deploy long range P2P networks compromising on radial coverage, throughput and/or spectra efficiency (310 km & 382 km) |
|
iBurst | 802.20 | Mobile Internet | HC-SDMA/TDD/MIMO | 95 | 36 | Cell Radius: 3–12 km Speed: 250 km/h Spectral Efficiency: 13 bits/s/Hz/cell Spectrum Reuse Factor: "1" |
EDGE Evolution | GSM | Mobile Internet | TDMA/FDD | 1.6 | 0.5 | 3GPP Release 7 |
UMTS W-CDMA HSDPA+HSUPA |
UMTS/3GSM | General 3G | CDMA/FDD CDMA/FDD/MIMO |
0.384 14.4 |
0.384 5.76 |
HSDPA is widely deployed. Typical downlink rates today 2 Mbit/s, ~200 kbit/s uplink; HSPA+ downlink up to 56 Mbit/s. |
UMTS-TDD | UMTS/3GSM | Mobile Internet | CDMA/TDD | 16 | Reported speeds according to IPWireless using 16QAM modulation similar to HSDPA+HSUPA | |
EV-DO Rel. 0 EV-DO Rev.A EV-DO Rev.B |
CDMA2000 | Mobile Internet | CDMA/FDD | 2.45 3.1 4.9xN |
0.15 1.8 1.8xN |
Rev B note: N is the number of 1.25 MHz chunks of spectrum used. EV-DO is not designed for voice, and requires a fallback to 1xRTT when a voice call is placed or received. |
Notes: All speeds are theoretical maximums and will vary by a number of factors, including the use of external antennae, distance from the tower and the ground speed (e.g. communications on a train may be poorer than when standing still). Usually the bandwidth is shared between several terminals. The performance of each technology is determined by a number of constraints, including the spectral efficiency of the technology, the cell sizes used, and the amount of spectrum available. For more information, see Comparison of wireless data standards.
For more comparison tables, see bit rate progress trends, comparison of mobile phone standards, spectral efficiency comparison table and OFDM system comparison table.
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