Providing Delay Guarantees in Bluetooth

Bluetooth polling, also referred to as Bluetooth MAC scheduling or intra-piconet scheduling, is the mechanism that schedules the traffic between the participants in a Bluetooth network. Hence, this mechanism is highly determining with respect to the delay packets experience in a Bluetooth network. In this paper we present a polling mechanism that provides delay guarantees in an efficient manner and we evaluate this polling mechanism by means of simulation. It is shown that this polling mechanism is able to provide delay guarantees while saving as much as possible resources, which can be used for transmission of best effort traffic or for retransmission

A Novel MAC Scheduling Algorithm for Bluetooth System

Data exchange within a Bluetooth piconet is masterdriven. The channel/slot utilization thus depends on the efficiency of the scheduling algorithm adopted by the master. In this paper, a novel MAC layer scheduling algorithm, called Floating Threshold (FT), is proposed. Unlike existing approaches, FT allows the master to estimate the backlog queue status at each slave accurately based only on a single feedback bit and a floating threshold. The master can then derive an optimized packet transmission schedule. Using simulations, we show that FT outperforms existing algorithms in terms of channel utilization, packet delay and packet dropping probability.published_or_final_versio

Cross-Layer Design to Maintain Earthquake Sensor Network Connectivity After Loss of Infrastructure

We present the design of a cross-layer protocol to maintain connectivity in an earthquake monitoring and early warning sensor network in the absence of communications infrastructure. Such systems, by design, warn of events that severely damage or destroy communications infrastructure. However, the data they provide is of critical importance to emergency and rescue decision making in the immediate aftermath of such events, as is continued early warning of aftershocks, tsunamis, or other subsequent dangers. Utilizing a beyond line-of-sight (BLOS) HF physical layer, we propose an adaptable cross-layer network design that meets these specialized requirements. We are able to provide ultra high connectivity (UHC) early warning on strict time deadlines under worst-case channel conditions along with providing sufficient capacity for continued seismic data collection from a 1000 sensor network.Comment: To be published in MILCOM 2012 - Track 2: Networking Protocols and Performanc

A simple adaptive MAC scheduling scheme for bluetooth scatternet

A simple adaptive MAC scheduling algorithm, called Gateway Oriented Scatternet Scheduling (GOSS), is proposed for data exchange in a Bluetooth scatternet. Unlike the existing scheme MDRP (Maximum Distance Rendezvous Point) that has a global superframe schedule shared by all gateways, the schedule used by each gateway is individually determined. Equal partition of the superframe schedule at a gateway to each connected piconet can thus be guaranteed, which enables a more robust performance than MDRP. In addition, GOSS allows a variable sized superframe at each gateway. To maximize its performance, the frame size can be dynamically adjusted according to the scatternet topology and traffic load in every predefined adaptation interval. Simulation results show that even a static GOSS prevails over MDRP. If the adaptation technique is used, further performance enhancement can be found.published_or_final_versio

MPEG-4 video transmission using distributed TDMA MAC protocol over IEEE 802.15.4 wireless technology

The issues of green technology nowadays give an inspiration to the researcher to make all the future design to be energy efficient. Medium Access Control (MAC) layer is the most effective layer to provide energy efficient due to its ability to control the physical radio directly. One of the important applications in the future is a video transmission that can be transmitted with low-cost and low power consumption. MPEG-4 is one of the international standards for moving video. MPEG-4 provide better compression and primarily design at low bit rate communication. In order to achieve good quality for video application, the design at MAC layer must be strong. Therefore, to increase the performance of the MPEG-4 in IEEE 802.15.4, in this paper we propose a cross layer design between MAC layer and Application layer. A priority queue will be implemented at MAC scheduling depends on the level of frame important in MPEG-4 format frame. A distributed Time division Multiple Access (TDMA) will be used for MAC protocol to provide reliable data transmission for high priority frame