The correct answer is: Multiple Access Scheme.
HSCSD (High Speed Circuit Switched Data) and GPRS (General Packet Radio Service) are both 2G mobile data technologies. However, they differ in the way they access the radio network. HSCSD uses a circuit-switched approach, while GPRS uses a packet-switched approach.
In a circuit-switched network, a dedicated circuit is established between the mobile device and the base station for the duration of the call. This means that the mobile device has exclusive use of the radio channel, which provides a high level of reliability and quality of service. However, it also means that the mobile device cannot use the radio channel for anything else while the call is in progress.
In a packet-switched network, data is transmitted in small packets. Each packet is assigned a unique address, and the packets are routed through the network independently of each other. This means that multiple mobile devices can share the same radio channel, which makes more efficient use of the available bandwidth. However, it also means that there is a greater risk of data being lost or corrupted, and the quality of service may be lower than in a circuit-switched network.
GPRS is a more efficient technology than HSCSD, and it offers a higher data rate. However, it is not as reliable as HSCSD, and the quality of service may be lower.
Here is a brief explanation of each option:
- Infrastructure: Both HSCSD and GPRS use the same infrastructure, which is the GSM network.
- Modulation technique: Both HSCSD and GPRS use the same modulation technique, which is GMSK (Gaussian Minimum Shift Keying).
- Switching Technique: HSCSD uses circuit switching, while GPRS uses packet switching.