Posts Tagged ‘backward compatibility’

About the CDMA2000

Written on November 4th, 2009 by MadChasno shouts

About the CDMA2000

There are different platforms or types of 3G technology. Each manufacturer has created and developed some of the most innovative products and mobile handsets. The CDMA2000 is one of the 3 major types. It has different features and tools also that will surely give you a whole new experience, unlike other technologies before it. Here are the details on how to make the most out of the specification.

Introduction

The CDMA2000 specification was created and developed by the Third Generation Partnership Project 2 or 3GPP2, which is a partnership that consists of 5 telecommunication standard bodies: TTC and ARIB in Japan, TTA in Korea, TIA in North America and CWTS in China. CDMA2000 has been implemented to a lot of networks as an evolutionary step from CDMAOne. CDMA2000 gives a full backward compatibility with IS-95B.

CDMA2000 is not contained only into a single IMT-2000 and, although managers have the ability to overlay ACDMA2000 1x system. The system backs 144 Kbps at present, with data rates running up to 307 Kbps in the near future, over the other present CDMAOne network.

Evolving the Technology

CDMA2000 1xEV is the other name of the evolved CDMA2000. This technology will be implemented via a number of steps, namely the 1xEV-DV and 1xEV-DO. 1xEV-DO which represents 1x Evolution Data Only. 1xEV-DV represents 1x Evolution Data and Voice. The two 1xEV CDMA2000 evolution steps will use a carrier standard 1.25 Mhz. 1xEV-DO will most likely be available for the operators CDMA2000 during 2002. The solutions for 1xEV-DV were made available in 2004.

CDMA2000 3x and CDMA2000 1x EV-DO are approved by ITU and IMT-2000 3G basics. CDMA2000 3x is a portion of what the ITU has called IMT-2000 CDMA MC or Multi Carrier. This uses a lower than 5 MHz spectrum via 3x 1.25 MHz channels to provide speeds of more than 2 Mbps.

The Technical Summary

As for the summary of the CDMA2000, the frequency band can be any type or existing and. The minimum frequency band needed for 1x is 2 x 1.25 MHz. For 3x, the required is 2 x 3.75 Mhz. Chip rate for 1x is 1.2288. For 3x, chip rate is 3.6864 Mcps.

The maximum user data rate for 1x is 144 Kbps at present and 307 Kbps in the near future. As for 1xEV-DO, the max rate is 384 Kbps to 2.4 Mbps. The frame length is 5 ms, 10 ms or 20 ms. As for power control rate, it is at 800 Hz. The spreading factors are 4 256 UL.

On WCDMA

W-CDMA in 3G is known as wideband code division multiple access. It is one of the main technologies used for the implementation of 3G cellular systems. It is founded on the radio access method give by ETSI Alpha group with the features and specifications finalized in 1999.

The implementation of W-CDMA will cover very technical details. The complexity of the systems can be seen from various angles. These include the complexity of the receiver, the complexity of the overall system and the complexity of the single algorithm.

In W-CDMA, the interface allows users of 3G to instantly send and get various data rates. UMTS networks will need the support of all current 2G services and several new services and applications. You should consider if this will be the right technique for you.

Bluetooth Versions

Written on December 26th, 2008 by MadChasno shouts

Bluetooth Versions

 

Version 1.1 and earlier
Since the technology of Bluetooth was introduced in 1998, several specification versions have been released. Versions 1.0 and 1.0B had too many issues and problems for manufacturers to develop devices for Bluetooth. The main issue was the lack of communication among the devices.

 

The core specification version 1.1 is the first successful operating version of Bluetooth. Version 1.1 corrected a majority of the bugs and problems found in earlier versions.

 

Version 1.2
Many of the newer Bluetooth devices, such as the newer cell phones are being sold with the newer Bluetooth version 1.2. This version offers backward compatibility with Bluetooth 1.1, faster transmission speeds, received signal strength, and a host controller interface (HCI) support for 3 wire UART.

 

Bluetooth version 2.0
It’s true that there may be multiple communication technologies, although they all share one common trait – faster is better. Bluetooth specialists realized this and therefore worked on improving the speeds of version 1.2. The newest version, version 2.0 + EDR (Enhanced Data Rate) was announced in 2004 and became available in late 2005.

 

Version 2.0 delivers data transfer rates of up to three times that of the original version of Bluetooth. Version 2.0 also provides enhanced connectivity. With Bluetooth 2.0 + EDR, you’ll be able to run more devices at the same time – with more efficiency.

 

Computers and even computer related devices are expected to be some of the first devices to en corporate Bluetooth 2.0 + EDR, followed of course by audio and imaging devices.

 

Version 2.0 is backward compatible with previous versions, three times faster and offers an enhanced data rate of 2.1 MB a second. It also offers broadcast and multicast support, along with a further enhanced bit error rate performance, making it the best Bluetooth has ever seen.

 

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