WirelessHART is one of the latest communication standards that have enhanced functionality and robustness. The standard is ideal for applications in control and automation industry. In this work we present an implementation the TDMA state machine of the WirelessHART communication protocol on TinyOS operating system using the nesC language for the Telobs motes. The development was carried out using software reuse principle and involved comparing the state diagram description of the TDMA presented in WirelessHART with that of the time synchronized frequency hopping implementation that was already available for reuse. The work highlights the differences between the TSCH code and the WirelessHART specifications and builds upon the TSCH code to arrive at the WirelessHART TDMA state machine implementation.

FlexRay communications system protocol is necessary specification of the future digitizing motor vehicle. Though the principal standard of specifications had established in 2005, little correlative commodities have used in the motor vehicle now. In this paper, I implement the hardware circuit of MAC Layer in the Flexray system. In the system, six major sub-modules: Controller Host Interface (CHI) is connecting with the Host processor interface, Protocol Operation Controller (POC) is controlling all sub-modules after receiving the orders from CHI, Clock Synchronization (CS) is synchronizing between all nodes, Media Access Control (MAC) is dividing slot and arranging the style of transmission data, Coding and Decoding (CODEC) is connecting the Physical Layer, and Frame and Symbol Processing (FSP) is detecting the error of receiving data. Because the system increases the function of synchronization between Nodes in the FlexRay system, it can transmit high data rate in the Time Division Multiple Access system (TDMA). Because the transmitter is two channels, it has the characteristic of high fault tolerance. The two characteristics meet the requirements that transmitting data is high data rate and stabilize.

This bachelor thesis has been carried out at the company Didamus which is located in Mjärdevi, Linköping. The company is currently developing a dive-console which aims to take the scuba diving experience to a whole new level and also to make scuba diving more secure. An assembly of scuba divers that can communicate with each other during a dive session might be the difference between life and death. Many seas around the world have muddy water which means poor visibility. In each situation a computer providing a scuba diver with information about others connected to the network, hazardous accidents can possibly be avoided.  The network itself consist of 10 nodes that need a network protocol which provides stability and reliability for every participant. The nodes themselves have a distributed responsibility to make the network reliable. The type of network implemented was a regular Time Division Multiple Access (TDMA) network where different nodes were given permission to access the medium in different instances of time. A global reference of time is always needed in a TDMA network to make it function properly. In a typical TDMA network a GPS-service gives each and every node information about the global time.  Unfortunately, GPS-services do not work well in water so a Master-Slave method was used instead. The master provides the rest of the nodes in the network with a global time reference. After a successful reception of a global time reference, the slave will be granted access to the network. The communication between the nodes is based on ultrasonic waves propagating in the water. The velocity of ultrasonic waves in water is only 1500 meters per second, explained in Discovery of Sound in the Sea by University of Rhode Island, which is a relatively slow signal speed. With the slow velocity taken into account an efficient TDMA protocol was developed, to perform communication under water.

Universiẗat, Diss., 2001--Kaiserslautern.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / The TmNS system employs a novel channel access approach to achieve efficient use of the available spectrum while still providing a reliable bi-directional telemetry link. At the heart of this process is the Link Manager which performs real time adjustments to the transmission windows of radios as it senses changes in network connectivity, transmit queue loading, and network management input. Dynamic network capacity control based on radio queue loading is presented as an example of an operation to be verified by modeling and simulation.

Wideband Code Division Multiple Access (WCDMA) is one of the main technologies for the implementation of third-generation (3G) cellular systems. It is based on radio access technique proposed by ETSI Alpha group and the specifications was finalised 1999. WCDMA is also known as UMTS and has been adopted as a standard by the ITU under the name “IMT-2000 direct spread”. The implementation of WCDMA will be a technical challenge because of its complexity and versatility. The complexity of WCDMA systems can be viewed from different angles: the complexity of each single algorithm, the complexity of the overall system and the computational complexity of a receiver. In WCDMA interface different users can simultaneously transmit at different data rates and data rates can even vary in time. WCDMA increases data transmission rates in GSM systems by using the CDMA air interface instead of TDMA. WCDMA is based on CDMA and is the technology used in UMTS. WCDMA is the dominating 3G technology, providing higher capacity for voice and data and higher data rates. The gradual evolution from today's systems is driven by demand for capacity, which is required by new and faster data based mobile services. WCDMA enables better use of available spectrum and more cost-efficient network solutions. The operator can gradually evolve from GSM to WCDMA, protecting investments by re-using the GSM core network and 2G/2.5G services. Orthogonal Frequency Division Multiplexing (OFDM) - technique for increasing the amount of information that can be carried over a wireless network uses an FDM modulation technique for transmitting large amounts of digital data over a radio wave. OFDM works by splitting the radio signal into multiple smaller sub-signals that are then transmitted simultaneously at different frequencies to the receiver. OFDM reduces the amount of crosstalk in signal transmissions. 802.11a WLAN, 802.16 and WiMAX technologies use OFDM. It's also used in the ETSI's HiperLAN/2 standard. In addition, Japan's Mobile Multimedia Access Communications (MMAC) WLAN broadband mobile technology uses OFDM. In frequency-division multiplexing, multiple signals, or carriers, are sent simultaneously over different frequencies between two points. However, FDM has an inherent problem: Wireless signals can travel multiple paths from transmitter to receiver (by bouncing off buildings, mountains and even passing airplanes); receivers can have trouble sorting all the resulting data out. Orthogonal FDM deals with this multipath problem by splitting carriers into smaller subcarriers, and then broadcasting those simultaneously. This reduces multipath distortion and reduces RF interference allowing for greater throughput. In this paper we have discussed about these two methods of third generation radio transmission system which are WCDMA and OFDM with various aspects. In between these two radio transmission technique, a better choice will be investigated.

The problem of finding a shortest TDMA is formally described as anInteger Program (IP). A brief user manual explains how the attached implementation can be used to find an optimal size TDMA for any givenWSN and routing table, fulfilling the validity criteria.

University, Diss., 2002--Kaiserslautern.

University, Diss., 2002--Kaiserslautern.

ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / As the integrated Network Enhanced Telemetry (iNET) program moves forward in resolving systems engineering design and architecture definition, critical technology “gaps” and a migration path to realizing the integration of this technology are needed to insure a smooth transition from the current legacy point to point telemetry links to a network oriented telemetry system. Specifically identified by the DoD aeronautical telemetry community is the need for a migration to a network solution for command, control, and transfer of test data by optimizing the physical, data link, and network layers. In this paper, we present a network centric telemetry preliminary architecture approach based on variants of 802.11 that leverages the open standards as well as the previous Advanced Range Telemetry (ARTM) work on the physical layer waveform. We present a burst modem approach based on the recent AOFDM 802.11a work, a TDMA-like MAC layer based on 802.11e, and then add additional MAC layer features to allow for the multi-hop aeronautical environment using a variant of the current working standard of 802.11s. The combined benefits of the variants obtained from 802.11a, 802.11e, and 802.11s address the needs for both spectrum efficiency in the aeronautical environment and the iNET program.