= GSM = [[http://www.heliostelecom.com/eproducts_detail.asp?id=105|GSM]] dates to the 1980s, when analog cellular systems in Nordic countries experienced rapid growth that resulted in the development of a new digital cellular standard. After five years of effort, 13 network operators and administrators signed a charter for the standardization of GSM. At that time, GSM was referred to by its French name, Group Special Mobile, but it is now known on a worldwide basis as Global System for Mobile Communications. The European version of GSM operates in the [[http://www.heliostelecom.com/eproducts_detail.asp?id=105|900MHz band]], which was avilable in countries that are members of the European commission. Unfortunately, the 900MHz band in the United States was not available, so the [[http://www.heliostelecom.com/eproducts_detail.asp?id=105|1900MHz band]] is used by GSM personal communications system in the United States. GSM represents a TDMA version of [[http://www.heliostelecom.com/eproducts_detail.asp?id=105|PCS]]. As a digital technology, voice is first compressed using a hybrid coder at approximately 13kps before the data is modulated. With this digital technolgy, you can connect a data source directly to a GSM cell phone without the use of a modem. However, the highest data rate that you can expect to obtain will be approximately 14.4kbps. Website: http://www.heliostelecom.com Company Name: Xiamen Helios Telecom Equipment Manufacture Inc. Department: Network Optimization Department Tags: [[http://www.heliostelecom.com/eproducts_detail.asp?id=105|RF Repeater]] | [[http://www.heliostelecom.com/eproducts_detail.asp?id=105|GSM Repeater]] | [[http://www.heliostelecom.com/eproducts_detail.asp?id=105|CDMA Repeater]] | [[http://www.heliostelecom.com/eproducts_detail.asp?id=105|UMTS Repeater]] | Wireless Solutions | Wireless Network Optimization