WCDMA frequency for Airtel & BSNL

[Ananika]

The recent NEWS all over is about the 3G and its use. Now frankly speaking I am not having any idea about the WCDMA. I just want to know about the WCDMA frequency for Airtel & BSNL. (Not thinking of Docomo). I am sure that you people must be knowing about it. Also please provide me with the more information about the WCDMA. I am curious to know about the basic concepts and technical aspects of WCDMA. Provide me more notes as possible, so that I will not have any doubt regarding the subject.

[hariharan_00]

I am sure that many users must not having deep knowledge about the WCDMA frequency. So I would say that along with the information about the WCDMA frequency for Airtel & BSNL, you should also know the basic concepts of it. Now coming to the point, I think that the frequency of BSNL's 3G connection is 2.1 GHz. Also, according to me the Airtel's 3G is only available for the iPhone. The Airtel's 3G will launch that service for Nokia's or Sony Ericsson's in coming days. So you will have to wait and watch...

[Pratim]

I am interested in discussing about the WCDMA frequency. WCDMA (Wideband Code Division Multiple Access - Access Code Division Multiple Broadband) is the air interface technology based on the UMTS (Universal Mobile Telecommunication System), which, in turn, is a European standard Third Generation (3G) wireless systems. WCDMA technology is highly optimized for high-quality communications of voice and multimedia communications, such as videoconferencing. It is also possible to access different services in one terminal, for example, we may be making a video and at the same time be doing a large file download, etc.. Can fully support multiple simultaneous connections such as an Internet connection, a telephone and video conferencing. This platform uses network protocols structures similar to that used in GSM (Global System for Mobile communications) is therefore the ability to use existing networks.

[pushpendra]

WCDMA offers flexibility in services, combining packet switching and circuit switching in the same channel with an average speed between 8 Kbps to 2 Mbps. Very efficiently using available radio spectrum, through the reuse of each cell, which requires 2 to 5 MHz for each layer, which means that a network will require 2 to 15 MHz, in a common spectrum band 2GHz. WCDMA terminals are less difficult to produce because they require very little signal processing, helping to keep down costs terminal. WCDMA supports connectivity IP (Internet Protocol), allowing for faster Internet access. The natural synergy between mobile communications and Internet access has spurred these are integrated. The fundamental technology on which work is switching IP packets. The path for the evolution of GSM to WCDMA, including a condition called GPRS (General Packet Radio Service) that provides packet switching up to 115 Kbps. Links from the WCDMA access network and core network using the latest GSM transmission protocol ATM mini-cells, known as ATM Adaptation Layer 2 (AAL2). This is the most efficient way of handling data packets to increase the capacity of a standard. E1/T1 lines can handle approximately 300 voice connections, compared with 30 of today's networks. The transmission cost savings are in the order of 50%. The new standard uses W-CDMA radio channels with a bandwidth of 5 MHz and makes a very efficient use of radio spectrum to achieve getting a data stream of up to 2 Mbit / s in local areas, which is reduced to 384 kbit / s in large areas, a value still well above the current 9.6 Kbps GSM are achieved in the 115 Kbps to reach in 2000 the new GSM2 +.

[NGV BalaKrishna]

The WCDMA concept is based on a new channel structure in all layers (L1 - L3) built on technology such as packet data channels and service multiplexing. This technology includes pilot symbols and structure of time slots. Third generation technology provides to its systems, the use of so called FRAMES (Future Radio Wideband Multiple Access Systems), these are Multiple Access Systems for Future Broadband Radio, which work with two types of access:

• FMA 1: TDMA broadband with or without relaxation, with a spacing of 1.6 MHz carrier
• FMA 2: WCDMA, with carrier spacing of 4.4. to 5.0 MHz.

The overall objective of FRAMES is to define a specification of air interface multiple access for UMTS (WCDMA), which will serve as a starting point for the UMTS standardization process and take all the compatibility of the above aspects for consideration in GMS / DCS.

[Damien25]

The FRAMES are structured in two sections of main tasks :

• The core system tasks (CTSYS), which directs the system specifications, which include the requirements and synthesis in order to liaise with potential UMTS operators. In addition, this kernel defines the air interface, network functions and implications for air access networks.
• The core demonstrator tasks (CTDEMO) is responsible for the design and implementation of the demonstrators based on job specifications made by the core CTSYS. An external link pages and standardization of work form the interface to other ACTS projects, so as to define common interfaces for system testing.

For the WCDMA air interface, the ETSI (European Telecommunications Standards Institute), provides for the use of duplexing technique, distributed according to the frequency bands as follows:

• WCDMA, FDD (Frequency Division Duplexing), for operation in any frequency band pairs. The FDD provides two distinct bands of frequencies for each user. The front band provides traffic from base station to the mobile and the band provides reverse traffic from the mobile to the base.
• TD / CDMA, TDD (Time Division Duplexing), for operation in frequency bands odd. The TDD uses time instead of frequency to provide both forward and backward links, provides two time slots on the same frequency simplex.

[taher]

The following are the Technical characteristics of the WCDMA radio interface:

• Basic rate of 4,096 Mbit chip carrier spaced from 4.4 to 5 MHz depending on the scenario or situation
• Multi-carrier spacing of 200 KHz to the ability of the Second Generation (2G)
• More high chip rate of 8,192 and 16,384 Mcps
• Variable rate entertainment for both directions
• Low and medium bit rates with a simple code
• High bit rate multicode solutions
• Coherent detection in both links: up and down
• Frame length of 10 milliseconds (ms)
• Asynchronous Operation
• Short Codes recreation and long codes in the uplink optional
• Recreation hybrid (variable spreading factor more multicode) to support variable rate transmission
• Flexible support for variable rate services
• Separation of data layer 1 and control in different physical channels
• Rate of explicit information
• Fast power control for both links: up and down