UMTS or Universal Mobile Telecommunications Service known as the 3G mobile technology, the third iteration of GSM. UMTS is based on the Wideband Code Division Multiple Access (WCDMA) technology, which enables multiple users to share the same frequency band simultaneously. It uses a combination of time division multiple access (TDMA) and code division multiple access (CDMA) techniques to achieve higher capacity and improved data transmission speeds.
UMTS introduced features like video calling and mobile television. Notably, it offers significantly higher data transfer rates while consuming less power compared to the older GSM technology. These enhanced data transfer speeds make UMTS suitable for high-speed Internet connections. However, it's important to consider the potential impact on battery life as UMTS consumes 50% more power than GSM in idle mode, making it crucial for IoT manufacturers to evaluate the trade-offs.
Uplink and downlink speeds are essential factors to consider for IoT manufacturers. Initially, UMTS boasted impressive downlink data rates of 384 kilobytes per second (Kbps), 40 times faster than GSM's 9.6 Kbps. Moreover, it outperformed technologies like General Packet Radio Service (53.6 Kbps) and Enhanced Data Rates for GSM Evolution (220 Kbps). Through subsequent advancements like High-Speed Packet Access (HSPA), evolved HSPA (HSPA+), and advanced HSPA+, UMTS data rates have been further improved. With advanced HSPA+, maximum download speeds of 168 megabits per second (Mbps) and maximum upload speeds of 22 Mbps are achievable.
UMTS is backward-compatible with GSM, which means that devices designed for GSM networks can also work on UMTS networks. This compatibility allows for the reuse of existing infrastructure and devices, making it easier to adopt UMTS connectivity for IoT deployments.
Packet-Switched Network vs. Circuit-Switched Network
UMTS operates on a packet-switched system, allowing devices to send data in small packets to the destination. This differs from circuit-switched networks that require a dedicated point-to-point connection. Packet-Switched Network: Data is transmitted in small packets over the network. Each packet contains not only the payload data but also addressing information for proper routing. The packets are sent individually and can take different paths to reach their destination. The network resources (such as bandwidth) are shared among multiple users and devices. Examples of packet-switched networks include IP (Internet Protocol) networks, which are used for internet connectivity.
Circuit-Switched Network
A dedicated communication path or circuit is established between two endpoints for the duration of the communication session. The circuit remains open for the entire conversation, even during periods of silence or no data transmission. Examples of circuit-switched networks include traditional telephone networks.
While UMTS has been popular among IoT manufacturers due to its lower power consumption compared to 4G LTE, and its higher data transfer rates than GSM. The UMTS infrastructure was primarily designed for cell phones, which have different connectivity needs than most IoT devices. Alternative options such as Narrowband-IoT (Nb-IoT) networks and Low Range Wide Area Networks (LoRaWANs) have been specifically developed for machine-to-machine connectivity.
