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Innovation in Digital Farming: Relevance in the Present Scenario
Published in Indu Bala, Kiran Ahuja, Harnessing the Internet of Things (IoT) for a Hyper-Connected Smart World, 2023
Ankur Singhal, Tarun Singhal, Vinay Bhatia, Deepak Dadwal, Himanshu Sharma
Global system for mobile communication (GSM) has the capability of lossless communication. GSM uses time division multiple access for digitization and compression of data. TDMA uses the same channel at different time slots for transmission of signals. GSM technology offers a better and proficient technique for the high production of crops. Sensors are used to determine the crop parameter. The measured value of parameters like humidity and temperature is compared with some predefined values, and the crop health is notified to the remotely located farmer with the help of GSM technology. The farmer receives crop health at a distance thus reduction in physical effort. The farmer can receive information about crop health from home by a message on phone in at any instant of time and in any weather, condition so can make better utilization of time in production growth. The integration of this technology with traditional methods will result in modernization in agriculture. The most significant obstacle in the production, growth of the crop is the lack of monitoring due to the distance between farmer homes and fields. This obstacle can be overcome by using GSM technology. GSM can be a solution to the agriculture environment monitoring problem. This can alarm farmers timely from upcoming threats. Cheap Internet and a wider range of connectivity can be back born for this technology. Many researchers are working in this field and proposed different cost and energy effective modules based on GSM technology.
Medium Access Control Protocols for Wireless Sensor Networks in a Pervasive Computing Paradigm
Published in Syed Ijlal Ali Shah, Mohammad Ilyas, Hussein T. Mouftah, Pervasive Communications Handbook, 2017
Muhammad K. Dhodhi, Syed Ijlal Shah, Marwan Fayed
As we have learned, CSMA is ideal for low traffic loads while it suffers from traffic contention under high traffic. On the other hand, TDMA avoids contentions and provides high channel utilizations under high traffic. In TDMA, nodes can only transmit during scheduled slots and under low contentions slots are wasted and channel utilization is reduced. The Z-MAC protocol combines the advantages of both TDMA and CSMA while offsetting their weaknesses. This is achieved by utilizing CSMA as a baseline protocol while switching to TDMA under high traffic contentions. Therefore, Z-MAC achieves high channel utilization and low-latency under low contention as in CSMA and it achieves high channel utilization under high contention and reduces collision among two-hop neighbors at a low cost similar to TDMA. Therefore, Z-MAC can dynamically adjust the behavior of MAC between CSMA and TDMA depending on the traffic contention and provide high performance at both ends of the utilization spectrum.
Contemporary Wireless Technologies
Published in G. S. V. Radha Krishna Rao, G. Radhamani, WiMAX, 2007
G. S. V. Radha Krishna Rao, G. Radhamani
In TDMA systems, several callers time-share a frequency channel. A call is sliced into a series of time slots, and each caller gets one time slot at regular intervals. Typically, a 39-kHz channel is divided into three time slots, which allows three callers to use the same channel. In this case, nine callers use three channels. The main advantage of the TDMA system is increased efficiency of transmission; TDMA systems can be used for transmission of both voice and data. They offer data rates from 64 kbps to 120 Mbps, which enables operators to offer personal communication services such as fax, voice-band data, and short messaging services (SMS). TDMA technology separates users in time, thus ensuring that they will not have interference from other simultaneous transmissions. It provides extended battery life because transmission occurs only part of the time. One of the disadvantages of TDMA is caused by the fact that each caller has a predefined time slot. The result is that when callers are roaming from one cell to another, all time slots in the next cell are already occupied, and the call might be disconnected. GSM is the best-known European implementation of services that use TDMA air interface technology. The other systems that deploy TDMA are DECT, the IS-136 standard, and Integrated Digital Enhanced Network (iDEN).
A permanent wireless dynamic monitoring system for the Colosseum in Rome
Published in Journal of Structural Integrity and Maintenance, 2018
Giorgio Monti, Fabio Fumagalli, Giuseppe Quaranta, Marco Sgroi, Marcello Tommasi
Communication is based on a proprietary protocol, which uses a Time Division Multiple Access (TDMA) mechanism to assign nodes of the network the time slots in which they can transmit. Frame duration and number of slots are configurable parameters. In a typical configuration, like the one used in the implementation deployed at the Colosseum, each frame has a duration of 250 ms and is divided in 32 slots. Two slots are allocated to the network coordinator, which transmits: (1) the ID of the transmission slots for all the terminals in the network as specified in the system configuration file, and (2) a synchronization message.
Interference Cancellation in Wireless Communications: Past, Present, and Future
Published in IETE Journal of Education, 2022
S. M. Zafaruddin, Pranay Bhardwaj
Time-division multiple access (TDMA) allocates the same channel for multiple users with distinct time slots, thereby avoiding multi-user interference. The TDMA is a digital multiple access scheme that requires precise synchronization between user data slots. On the other hand, multiple users with unique orthogonal codes share a channel with a larger bandwidth simultaneously without interference using the code division multiple access (CDMA) technology. In practice, the CDMA exhibits multi-user interference since the generation of perfect orthogonal codes for a large number of users is notfeasible.