3G Connectivity

3G connectivity of mobile telecommunications technology popularly known as 3G is an International Telecommunication Union (ITU) specification that promised an increase in bandwidth of up-to 384kbps.

W-CDMA The original and most widespread radio interface is called W-CDMA. The TD-SCDMA radio interface was commercialized in 2009 and is only offered in China. The latest UMTS release, can provide peak data rates up to 56 Mbit/s in the down-link in theory (28 Mbit/s in existing services) and 22 Mbit/s in the up-link.

The CDMA200 system, first offered in 2002, standardized by 3GPP2 used especially in North America and South Korea, sharing infrastructure with the 2G standard. The cell phones are typically CDMA2000 and IS-95 hybrids. The latest release EVDO Rev B offers peak rates of 14.7 Mbit/s downstream.

The above systems and radio interfaces are based on radio transmission technology. While the standard (“2.9G”),  cordless phones and Mobile WiMAX standards formally also fulfill the IMT-2000 requirements and are approved as 3G standards by ITU, these are typically not branded 3G, and are based on completely different technologies.

The following common standards comply with the IMT2000/3G standard:
A revision by the 3GPP organization to the older 2G GSM based transmission methods, utilizing the same switching nodes, base station sites and frequencies as GPRS, but new base station and cellphone RF circuits.

It is based on the three times as efficient 8PSK modulation scheme as supplement to the original GMSK modulation scheme. EDGE is still used extensively due to its ease of upgrade from existing 2G GSM infrastructure and cell-phones.

EDGE combined with the GPRS 2.5G technology is called “EGPRS” and allows peak data rates in the order of 200 kbit/s, just as the original UMTS and  WCDMA versions, and thus formally fulfills the IMT2000 requirements on 3G systems.

However, in practice EDGE is seldom marketed as a 3G system, but a 2.9G  system. EDGE shows slightly better system spectral efficiency than the original UMTS and CDMA2000 systems, but it is difficult to reach much higher peak data rates due to the limited GSM spectral bandwidth of 200 kHz, and it is thus a dead end. EDGE was also a mode in the IS-135 TDMA system, ceased today.

Evolved EDGE, the latest revision, has peaks of 1 Mbit/s downstream and 400 kbit/s upstream, but is not commercially used. The Universal Mobile Telecommunications System created and revised by the 3GPP. The family is a full revision from GSM in terms of encoding methods and hardware, although some GSM sites can be retrofitted to broadcast in the UMTS/W-CDMA format.