An overview
We all know that telecommunications has evolved tremendously from telegraphs to the telephones and the current smart phones. This evolution not only involved the user equipment, but also the technology.
The technologies used for telecommunications have changed greatly over the last 50 years. Empowered by research into semiconductors and digital electronics in the telecommunications industry, analog representations of voice, images, and video have been replaced by digital representations. The major consequence has been that all types of media can be represented in the same basic form (i.e., as a stream of bits) and therefore handled uniformly within a common infrastructure (most commonly as Internet Protocol or IP, data streams). Subsequently, circuit switching was supplemented by, and will likely ultimately be replaced by, packet switching.
The most fundamental change, both in terms of technology and its implications for industry structure, has occurred in the architecture of telecommunications networks.
How are the networks different?
First, they are integrated. All media, be it voice, audio, video, or data are increasingly communicated over a single common network. This integration offers economies of scope and scale in both capital expenditures and operational costs. In addition, it also allows different media to be mixed within common applications. As a result, both technology suppliers and service providers are increasingly in the business of providing telecommunications in all media simultaneously rather than specializing in a particular type such as voice, video, or data.
Second, the networks are built in layers. Starting from the physical layer, which is concerned with the mechanical, electrical and optical, and functional and procedural means for managing network connections to the data, network, and transport layers, which are concerned with transferring data, routing data across networks between addresses, and ensuring end-to-end connections and reliability of data transfer to the application layer, which is concerned with providing a particular functionality using the network and with the interface to the user.
Evolution
The paradigm has changed since the early analog mobile generation (1G) to the last implemented fifth generation (5G). The new mobile generations do not pretend to improve the voice communication experience but try to give the user access to a new global communication reality, via data packets. The aim is to reach communication ubiquity and to provide users with a new set of services.
The first operational cellular communication system was deployed in Norway. These first generation (1G) systems provided voice transmissions by using frequencies around 900 MHz and analog modulation.
The second generation (2G) of the wireless mobile network was based on low-band digital data signaling. The most popular 2G wireless technology is known as Global Systems for Mobile Communications (GSM). The first GSM systems used a 25 MHz frequency spectrum in the 900 MHz band. The two schemes Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) schemes were used to allow simultaneous calls on the same frequency.
While GSM was developed in Europe, Code Division Multiple Access (CDMA) was developed by Qualcomm in North America. CDMA uses spread spectrum technology to break up speech into small, digitized segments and encodes them to identify each call. The technology distinguishes between multiple transmissions carried simultaneously on a single wireless signal.
The 2G technologies mentioned above, are based on circuit-switch technology and can handle data rates of upto 9.6 kbps and hence not suitable for web browsing and multimedia applications.
This led to a new technology - General Packet Radio Service (GPRS) which was known as 2.5G. GPRS provides both a means to aggregate radio channels for higher data bandwidth (up to 60 kbps) and the additional servers required to off-load packet traffic from the existing GSM technology.
In the world of 2G, voice takes precedence over data which is already dominant in the wireline communications. So, there was a need to overcome the painfully slow data connections and enahance the speed. The idea behind developing the 3G technology was to prepare a universal infrastructure able to carry existing and also future services and provide better quality data service to the user, thus generating more revenue to the operators.
Features
The advantages of 3G over the previous networks are enormous:
- High data rates – up to 2 Mbps
- Security – by allowing the UE to authenticate the network it is connecting to; user can be sure that this is the intended network
- Several times higher data speed – downlink/uplink – up to 2 Mbps
- Enhanced audio and video streaming
- Video-conferencing support
- Web and WAP browsing at higher speeds
- IPTV support
Due to the requirement of a new technology and bandwidth, 3G wireless needed to be built on a new infrastructure. See figure below for the 3G (W-CDMA) architecture).
With the advent of mobile internet access, suddenly the circuit-based backhaul network from the base station and back had to significantly change. 3G systems are IP-centric and will justify an all-IP infrastructure.
Issues foreseen
When it became clear that the real killer application was the internet, it was obvious that users would want data access on-the-go. A huge capital is required to build the 3G infrastructure. So, this is a huge setup to transport the speech signals over the given channel width.
The significant issues foreseen with the 3G setup and users' demand for internet on-the-go are:
- High spectrum licensing fees for the spectrum
- Huge capital required to build infrastructure for services
- High prices for mobile services
Conclusion
There will be no flip to this technology, but only evolution. 3G services will add invaluable dimension for the integral part of the modern world. In the near future, 3G services will not be considered as a value-add, but a fundamental aspect.
References: Wiley's and internet
