You might have heard of 3G and 4G networks, but do you know what makes them different? And why is 3G architecture more efficient than 4G networks in some aspects? In this article, you will learn about the main features and benefits of 3G architecture and protocols, and how they compare to 4G networks.
3G stands for third generation of mobile communication systems, and it was developed to offer faster and more reliable data transmission than previous generations. 3G networks use a combination of circuit-switched and packet-switched technologies, which means that they can handle both voice and data traffic efficiently. 3G networks also support a variety of services, such as multimedia messaging, video streaming, web browsing, and location-based applications.
2G and 3G are truly mobile generations and there's nothing wrong in referring to them as such. However 4G and beyond need to be called wireless generations as they support both mobile and FWA.
(3G to 5G) In 3G networks, base stations typically consisted of integrated units housing both the radio transceivers and baseband processing functions. With the advent of 4G LTE technology, there was a shift towards separating the radio and baseband processing functions, leading to the introduction of Remote Radio Heads (RRHs) or Remote Radio Units (RRUs). But 5G network architecture is a vast improvement upon previous architectures. Huge leaps in performance are made possible by large cell-dense networks. The transition to 5G has further driven the disaggregation of network functions and introduced concepts like Virtualized Radio Access Network (vRAN) or Cloud RAN (C-RAN).
3G architecture consists of three main components: the user equipment (UE), the UMTS terrestrial radio access network (UTRAN), and the core network (CN). The UE is the device that connects to the network, such as a mobile phone or a laptop. The UTRAN is the part of the network that provides radio access and manages the radio resources. The UTRAN consists of two elements: the node B, which is the base station that communicates with the UE, and the radio network controller (RNC), which controls the node B and the radio interface. The CN is the part of the network that connects the UTRAN to other networks, such as the internet or the public switched telephone network (PSTN). The CN consists of two domains: the circuit-switched domain (CSD), which handles voice calls and SMS, and the packet-switched domain (PSD), which handles data services and IP-based applications.
Both 2G and 3G network architectures are distributed control plane architectures. The RNCs are distributed in the network in multiple locations.
3G protocols are the rules and standards that govern how the network components communicate with each other and with other networks. These protocols are based on the International Mobile Telecommunications-2000 (IMT-2000) framework, which defines a set of specifications for 3G systems. To elaborate, the air interface protocol defines how the UE and the node B exchange radio signals, typically using Wideband Code Division Multiple Access (WCDMA). The radio access network protocol is based on the Iub interface and uses ATM (Asynchronous Transfer Mode) technology to transport voice and data packets. Lastly, the core network protocol is based on the Iu interface and uses IP (Internet Protocol) technology to connect the CSD and the PSD domains.
It also needs to mention the 3gpp standards (called releases) along with the ITU standards. R99-R7 are the relevant 3gpp standards. IMT 2000 includes the early releases of 4G as well, namely R8 and R9.
3G architecture and protocols offer several advantages over 4G networks in terms of efficiency. For example, 3G networks use a hybrid of circuit-switched and packet-switched technologies, which optimizes network resources and reduces latency and congestion. 4G networks, conversely, rely solely on packet-switched technologies, which can cause delays and bottlenecks when the traffic is high or the network is congested. Additionally, 3G networks use WCDMA as the air interface protocol, which has a higher spectral efficiency and better performance in multipath and fading environments than OFDMA. WCDMA also has a lower power consumption and longer battery life than OFDMA. Furthermore, 3G networks use ATM as the transport technology for the Iub interface, which has a higher reliability, lower overhead, better quality of service, and lower jitter than IP.
Actually, 4G networks, which are E2E IP, generally virtualized and with centralized control, give more advantages over 3G. Further OFDMA used by LTE gives more spectral efficiency than CDMA used in UMTS.
3G architecture and protocols have some limitations and drawbacks compared to 4G networks. These include a lower data rate and bandwidth, which limits the quality and variety of services and applications that can be offered. 3G networks have a higher complexity and cost than 4G networks, with more hardware, software components, interfaces, and protocols, leading to higher capital and operational expenses for network operators. Additionally, 3G networks have a lower compatibility and interoperability than 4G networks, hindering user mobility and flexibility. This is due to 3G networks using different standards and frequencies in different regions and countries, whereas 4G networks use a common standard and frequency for seamless global connectivity.