AM is an older analog modulation technique where the amplitude (strength) of the carrier wave is varied in accordance with the audio signal (voice or data).
2. FM (Frequency Modulation):
FM is also an analog modulation technique where the frequency of the carrier wave is varied to represent the audio signal. FM is less susceptible to interference and noise than AM and generally provides higher quality sound.
3. GSM (Global System for Mobile Communications):
GSM is a cellular network technology that uses digital modulation and multiple access technologies to provide voice and data services. GSM is widely used worldwide and supports various radio communication technologies, including GPRS (General Packet Radio Service), EDGE (Enhanced Data Rates for GSM Evolution), and 3G (third generation).
4. CDMA (Code Division Multiple Access):
CDMA is another cellular network technology that uses a spread spectrum technique called direct-sequence spread spectrum (DS-SS) to transmit and receive signals. CDMA provides improved capacity and efficiency compared to GSM and is used by several wireless carriers around the globe.
5. TDMA (Time Division Multiple Access):
TDMA is a digital modulation technique that divides the available bandwidth into time slots and assigns them to different users. TDMA allows multiple users to share the same frequency simultaneously and is commonly used in older wireless communication standards like 2G and 3G.
6. Bluetooth:
Bluetooth is a short-range wireless technology used for connecting devices such as smartphones, headphones, printers, and speakers. Bluetooth operates in the ISM (industrial, scientific, and medical) band (2.4GHz), enabling wireless data transfer over short distances.
7. Wi-Fi (Wireless Fidelity):
Wi-Fi is a widely adopted wireless networking technology that allows devices to connect to the internet and communicate wirelessly within a local area network (LAN). Wi-Fi uses radio waves in the 2.4GHz and 5GHz bands and supports high-speed data transmission for devices like laptops, smartphones, tablets, and smart TVs.
8. ZigBee:
ZigBee is a low-power wireless communication protocol designed for monitoring and controlling devices in energy-efficient, low-data rate IoT applications like smart homes, industrial automation, and wireless sensor networks.
9. NFC (Near Field Communication):
NFC is a short-range wireless technology used for contactless payments, data exchange, and device connectivity. NFC operates at a frequency of 13.56 MHz and allows devices to communicate when they are within a few centimeters of each other.
10. UWB (Ultra-Wideband):
UWB is a high-bandwidth, low-power wireless technology that uses ultra-wide frequency bands to transmit large amounts of data at high speeds. UWB is being explored for various applications, including wireless video streaming, imaging, and communication.