Cross-Layer Design for Efficient Wireless Medium Access Using Adaptive Multiuser Detection by Kristoffer Norman Bruvold We jointly optimize the physical (PHY) and medium access control (MAC) layers for enabling rapid, contention-based wireless medium access. The key new features of our cross-layer design are multipacket reception (MPR) capability and the ability to estimate the number of conten...

In this work, a new control scheme for synchronization of AC microgrids with upstream power grid is presented. The effects of V2Gs (vehicle to grid) dynamics on synchronization process is studied. This new control approach is based on the optimal fractional calculus and has been developed for synchronization of the microgrid. The V2Gs effect on the dynamics of the microgrid is analyzed through ...

Underwater acoustic communication is widely used in many areas to collect the data from different kinds of sensors deployed underwater or send control information to remote nodes. However, there are many challenges for underwater communication systems because of the characteristics of acoustic propagation in the underwater environment, such as Doppler spread, ambient noise, fading, high propaga...

Im Rahmen eines Blockseminars zur Didaktik der Informatik wurde ein Unterrichtsentwurf zum Thema Datenkollision erstellt und anschließend in einer 12. Klasse getestet. Hierbei wurde das ALOHA-Protokoll als Beispiel eines nicht kollisionsfreien Protokolls gewählt, da es zum einen sehr einfach aufgebaut ist und zum anderen trotzdem eine bessere Leistung bringt, als man intuitiv erwartet hätte. De...

A reservation-based MAC protocol has been adopted by standards bodies as the basic protocol for data communication within the upstream channel of a cable plant. The available capacity is divided in two separate channels. One is a random access channel, or contention channel, used to send requests to the head-end, with the possibility of collisions occurring therein. When collisions happen, they...

We investigate the effect of limiting the number of retransmission trials on the stability of slotted ALOHA systems with no capture effect. Using an argument of the catastrophe theory, we prove that a slotted ALOHA system is mono-stable, if the number of retransmission trials is limited to, at most, eight. We also show how the bistable region is enlarged, as the number of retransmission trials ...

Nonorthogonal Code Shift Keying Code Division Multiple Access (CSK/CDMA) ALOHA is expected to improve the throughput in advanced wireless network, such as sensor networks and ad-hoc networks. The throughput of the nonorthogonal CSK/CDMA ALOHA is expected to get better by introducing interference cancellation technique. It is not clear how much the throughput improved by introducing interference...

This paper develops a novel slotted ALOHA protocol (Direction-Of-Arrival ALOHA) for use in ad hoc networks where nodes are equipped with smart antennas. The protocol relies on the ability of the antenna and DOA algorithms to identify the direction of the desired signal and the direction of the interferers to maximize SINR (Signal to Interference and Noise Ratio) at the receiver. The performance...