The progression of wireless data technologies from 2G to 3G promises faster transmission speeds. But before you choose your transport technology, it's important to know each one's advantages and disadvantages.
| Transport technology | Description | Typical use/
Data transmission speed | Pros/cons |
| TDMA | Time Division Multiple Access is 2G technology | Voice and data
Up to 9.6kbps | Low battery consumption, but transmission is one-way, and its speed pales next to 3G technologies |
|
| GSM | Global System for Mobile Communications is a 2G digital cell phone technology | Voice and data. This European system uses the 900MHz and 1.8GHz frequencies. In the United States it operates in the 1.9GHz PCS band
Up to 9.6kbps | Popular around the globe. Worldwide roaming in about 180 countries, but GSM's short messaging service (GSM-SMS) only transmits one-way, and can only deliver messages up to 160 characters long |
|
| GPRS | General Packet Radio Service is a 2.5G network that supports data packets | Data
Up to 115kbps; the AT&T Wireless GPRS network will transmit data at 40kbps to 60kbps | Messages not limited to 160 characters, like GSM SMS |
|
| EDGE | Enhanced Data GSM Environment is a 3G digital network | Data
Up to 384kbps | May be temporary solution for operators unable to get W-CDMA licenses |
|
| CDMA | Code Division Multiple Access is a 2G technology developed by Qualcomm that is transitioning to 3G | | Although behind TDMA in number of subscribers, this fast-growing technology has more capacity than TDMA |
|
| W-CDMA (UMTS) | Wideband CDMA (also known as Universal Mobile Telecommunications System--UMTS) is 3G technology. On November 6, 2002, NTT DoCoMo, Ericsson, Nokia, and Siemens agreed on licensing arrangements for W-CDMA, which should set a benchmark for royalty rates | Voice and data. UMTS is being designed to offer speeds of at least 144kbps to users in fast-moving vehicles
Up to 2Mbps initially. Up to 10Mbps by 2005, according to designers | Likely to be dominant outside the United States, and therefore good for roaming globally. Commitments from U.S. operators are currently lacking, though AT&T Wireless performed UMTS tests in 2002. Primarily to be implemented in Asia-Pacific region |
|
| CDMA2000 1xRTT | A 3G technology, 1xRTT is the first phase of CDMA2000 | Voice and data
Up to 144kbps | Proponents say migration from TDMA is simpler with CDMA2000 than W-CDMA, and that spectrum use is more efficient. But W-CDMA will likely be more common in Europe |
|
| CDMA2000 1xEV-DO | Delivers data on a separate channel | Data
Up to 2.4Mbps | (see CDMA2000 1xRTT above) |
|
| CDMA2000 1xEV-DV | Integrates voice and data on the same channel | Voice and data
Up to 2.4Mbps | (see CDMA2000 1xRTT above) |
|
| |
0 Comments:
Post a Comment
<< Home