What is US-TDMA IS-136, one of the 2nd generation systems mainly in USA

You're absolutely right! US-TDMA, in this context, refers to IS-136, a second-generation (2G) cellular communication standard based on Time-Division Multiple Access (TDMA) technology. It was primarily deployed in the United States and Canada during the 1990s. Here's a technical breakdown of US-TDMA (IS-136):

Core Technology:

• US-TDMA (IS-136) utilizes TDMA, a multiple access technique that divides the available radio channel into time slots.
• Each user equipment (UE) like a mobile phone is assigned specific time slots within a frame to transmit and receive data. This allows multiple users to share the same frequency channel without interference.

Evolution from IS-54:

• IS-136 is an evolution of the earlier IS-54 standard, another TDMA system.
• IS-136 built upon IS-54 by introducing several enhancements, including:
  • Text messaging: Enabled SMS (Short Message Service) for text communication between mobile phones.
  • Circuit switched data (CSD): Provided a way to establish a temporary data connection for basic data transfer needs.
  • Improved data compression: Allowed for more efficient transmission of voice data within the allocated time slots.

Technical Specifications:

• Frequency band: Primarily operated in the 800 MHz band, although some variations used other bands like 1900 MHz.
• Channel bandwidth: Utilized 30 kHz channels, similar to its predecessor IS-54.
• Data rate: Offered voice communication rates up to 14.4 kbps and data transfer rates of up to 9.6 kbps.
• Network architecture: Employed a cellular network structure with base stations handling communication with mobile devices within their coverage area.

Deployment and Legacy:

• US-TDMA (IS-136) was a dominant cellular technology in the US and Canada during the 1990s. It played a crucial role in enabling basic mobile phone functionalities like voice calls and text messaging.
• However, with the emergence of 2.5G technologies like GPRS and the eventual transition to 3G standards like UMTS, US-TDMA (IS-136) has been largely phased out.
• Today, most cellular networks in these regions operate on more advanced technologies offering higher data rates and improved capabilities.

Comparison with Other 2G Standards:

• Compared to other 2G standards like GSM (Global System for Mobile communication), US-TDMA (IS-136) offered a simpler and potentially more cost-effective approach.
• However, GSM offered wider international roaming capabilities due to its global adoption.

Conclusion:

US-TDMA (IS-136) stands as a significant chapter in the history of mobile communication in the United States and Canada. It provided a foundation for early mobile phone functionalities and paved the way for the evolution towards more advanced cellular technologies. Understanding US-TDMA (IS-136) offers insights into the technological advancements that have shaped our current mobile communication landscape.