High speed circuit switched data

Basic Overview

High Speed ​​Circuit Exchange Data (HSCSD, High-Speed ​​Circuit-Switch Data) Allows mobile users to exchange data with 38.4 kbps speed, this speed is global than 1999 The standard speed of the mobile communication system (GSM) is four times. The speed of high-speed circuit exchange data is compatible with many computer modems that communicate with the currently fixed telephone network.

High Speed ​​Circuit Exchange Data (HSCSD) standard still needs to be improved, and the final goal is part of the Universal Mobile Communication Service (UMTS).

High Speed ​​Circuit Exchange Data Method and Circuit Exchange Data Differentiated by using different coding methods and / or multiple time slots to increase data transmission amount. HSCSD is a choice of communication technology EDGE and UMTS systems with higher transmission rates.

Innovation

HSCSD technology is an innovation in the use of different data error correction methods for data transmission. Initially, the error correction mode in the GSM system is designed to work within a limited coverage and can work in the worst situation that can be affected by the GSM system. This means a large part of the GSM transmission amount is used to correct the code. HSCSD provides different levels of error correction methods depending on the different conditions of wireless connection. That is, in the optimum case, the HSCSD can be transmitted at 14.4 kbit / s in a time slot, and in the CSD mode, only 9.6 kbit / s transmission speed can be provided. The transmission capacity has increased by 50%. Another innovation of

HSCSD is that multiple time slot transmission data can be used at the same time. At the same time, 4 time slot transmission can provide 57.6kbit / s (4 * 14.4 kbit / s) transmission speed, even if the channel condition is not good, the error correction ability is used for data transmission, HSCSD is still It is possible to provide a high 4-fold transmission speed than the CSD mode (38.4kbit / s vs 9.6kbit / s). At the same time, the transmission rate of 115kbit / s can be provided with the 8GSM time slot.

typically, the HSCSD user is more than ordinary users, and the charge is determined by the number of time slots assigned. This makes HSCSE look relatively expensive, and another technology - one of the relatively inexpensive and more popular GPRs based on package exchange. GPRS charges are based on the amount of data, and HSCSD is based on connection time.

Comprehensive review

In addition to this advantage of the user, HSCSD is delayed than the lower wireless interface than GPRS, because the HSCSD connection does not have to wait for a package Network license. In the UMTS system, HSCSD is not that obvious, because the UMTS wireless interface is designed for high bandwidth, low-delay package switching system. This means that in the UMTS system, the advantages of HSCSD technology can only be reflected in the traditional dial-up system.