A novel mac scheduling algorithm for bluetooth system

Cluster Computing, 2002

The paper focuses on one of the emerging technologies for constructing a Mobile ad hoc network: Bluetooth. Bluetooth can be exploited on small scales, to build ad hoc wireless Personal Area Networks (WPAN), i.e., networks that connect devices placed inside a circle with radius of 10 m. The Bluetooth technology is just starting to appear on the market and its architecture and protocols are not widely known. For this reason, the first part of the paper contains a tutorial-oriented description of the Bluetooth architecture and protocols. In addition, in the paper we extensively discuss the performance of this technology by investigating, through simulation, the main performance figures: the protocol efficiency (channel utilization), the response time, and the system power (i.e., the ratio between throughput and delay). Specifically, the performance analysis focuses on the algorithms for scheduling the transmissions in a Bluetooth network. The Bluetooth Specification indicates a Round Robin scheduler as possible solution, that is each slaves is polled in a consecutive order. For this reason, we first study in depth the performance figures of a Bluetooth network with a Round Robin scheduler. Our results point out the inefficient Bluetooth behavior under asymmetric traffic conditions. To solve this problem we propose and analyze an innovative scheduling algorithm specifically tailored to the Bluetooth characteristic. This algorithm, named efficient double-cycle (EDC), dynamically adapts the polling frequency to the traffic conditions. A performance study indicates that our EDC scheduler always outperforms the Round Robin scheduler.

Proc. WiOpt'03, 2003

In this paper we present a framework for performance evaluation of a Bluetooth piconet using multislot packets. In particular, under some classical assumptions, we develop a model of a Bluetooth network and derive the complete statistics of the one-hop delay, and other significant metrics such as the channel utilization parameter. Stability conditions are investigated and it is shown that the use of multi-slot packets enlarges the achievable rate region. Simulations results are then shown, which validate the proposed analysis.

[Host publication title missing]; pp 139-150 (1999), 1999

During the last couple of years, much attention has been brought to research and development of mobile ad hoc networks. In an ad hoc network, a collection of peer wireless mobile users within range of each other may dynamically form a temporary network without the use of any existing network infrastructure or centralized server, as opposed to cellular systems. This paper analyses the performance of a wireless ad-hoc network concept called Bluetooth which was presented in February 1998 by its five promoters-Ericsson, Nokia, IBM, Toshiba and Intel. We discuss a modified exhaustive scheduler, proposed by the authors, and show its applicability under various operating conditions. A number of scenarios are analyzed and we also address the importance of multi-slot packets to increase throughput and to keep the delays low.

2000 IEEE International Conference on Personal Wireless Communications. Conference Proceedings (Cat. No.00TH8488)

Abstracf-Bluetooth is a fast emerging standard for inddor pico-cellular wireless networks. Power is at a premium in typical Bluetooth devices like palmtops, PDAs, laptops and mobile phones. The Bluetooth standard defines various modes for reducing power consumption of the devices by reducing their transmission and reception activities. System throughput can be increased by keeping Bluetooth devices in low power mode in case of low data rates at those devices, by avoiding unnecessary polling packets. In this paper we propose policies for scheduling and switching of power modes of Bluetooth devices for increasing throughput and decreasing power consumption. All the proposed scMmes, along with a policy where all the devices are always in active mode, and a policy with previous information of packet arrival times are implemented on a Bluetooth simulator for comparing their performance. Performance of the policies is compared for Merent tr-c models and actual traffic traces. The policies are found to perform well in terms of power savings and throughput enhancement.

In this paper, we focus on the ability of Bluetooth to support Quality of Service (QoS) requirements expressed by QoS sensitive applications. The QoS perceived by the application depends on the efficiency of the scheduling schemes chosen at the medium access layer. We focus on two QoS constraints : the importance degree of a message and its delivery deadline. As no existing Bluetooth scheduling simultaneously accounts for these two QoS constraints, we define a new Bluetooth global scheduling, called Class-Based Earliest Deadline First (CB-EDF). Simulation results show that CB-EDF achieves a good service differentiation and allows the coexistence of messages with different application constraints. By means of simulations, we determine the CB-EDF settings that offer a good service differentiation for any traffic distribution. Moreover, we show that CB-EDF is a flexible solution that dynamically adapts to traffic changes.

INFOCOM 2004. Twenty- …, 2004

Bluetooth is a promising wireless technology aiming at supporting electronic devices to be instantly interconnected into short-range ad hoc networks. The Bluetooth medium access control protocol is based on the Master/Slave concept wherein any communication between slave devices has to go through the Master. While this model is simple, it incurs longer delay between any two slave devices due to the use of non-optimal packet forwarding scheme and the use of double the bandwidth at the Master. Moreover, if more than two devices want to communicate as a group, this can only be achieved by either multiple unicast transmissions or a piconet-wide broadcast from the master. To handle these issues efficiently, we propose a novel combination of Dynamic Slot Assignment (DSA) and piconet partitioning. With DSA, the piconet Master dynamically assigns slots to Slaves so as to allow them to communicate directly with each other without any intervention from the Master. Such proposed communication architecture provides for Quality of Service (QoS) requests, admission control, and multi-device conversation by which a multicast-like communication is feasible within a piconet. To widen the scope of DSA, we propose QoS-driven Enhanced DSA (EDSA) where dynamic piconet partitioning and scatternet support comes into picture. Devices are grouped in piconets according to their connection endpoints in EDSA, enabling it to be employed over a scatternet. We have performed extensive simulations and observe that these schemes drastically enhance Bluetooth performance in terms of delay and throughput, while significantly reducing network power consumption. I.

Bluetooth includes the concept of devices participating in multiple "piconets" interconnected via bridge devices and thereby forming a "scatternet". This paper presents a scheme for Bluetooth scatternet operation that adapts to varying traffic patterns. According to the traffic information of all masters that the bridge is connected, the bridge switches to the masters with high traffic loads and increase the usage of the bridge. In addition, load adaptive interpiconet scheduling can reduce the number of failed unsniffs and the overhead of the bridge switch wastes to further increase the overall system performance.

International Journal of Wireless Information Networks, 2020

Bluetooth Low Energy (BLE) is one of the most important technologies that feed the growing field of Internet of Things and Wireless Sensor Networks. Due to its flexibility and unique low power-consumption, an increasing number of industrial devices, household appliances and wearables are being designed using it. However, the real-time demands of these networks such as timing and Quality of Service are not fully covered by the protocol itself. To help improve and offer some control over these characteristics, this paper presents a time slot transmission scheme with packet prioritization. It is based on the division and allocation of the connection interval to two types of messages: real-time and ordinary. The goal is to offer the lowest packet loss and time guarantees for real-time messages, while providing acceptable throughput for ordinary ones. Since the probability of a BLE connection to close increases with the number of packets sent through it, the position where a real-time packet is being sent as well as the number of ordinary messages in a connection represent key factors. The use of the first and last slot for real-time packets with ordinary flow restricted to the space between them decreases the transmission delay uncertainty and allows probability tuning based on the number of ordinary messages. Simulations were performed using the proposed scheme and a reduction of more than 100 times in the delay variance was observed for real-time transmissions. Regarding reliability, around 5% of the packets were lost for a bit error rate of 10 −3 .

Networks - The Proceedings of the Joint International Conference on Wireless LANs and Home Networks (ICWLHN 2002) and Networking (ICN 2002), 2002

Bluetooth is a universal radio interface in the 2.45Ghz frequency band, which will enable users to connect a wide range of small electronic devices such as notebook computers, cellular phones etc. Two or more Bluetooth-enabled devices that come within range of each other can set up an ad hoc network, called a piconet. Within a piconet, one unit becomes the master and controls access to the channel. The rest of the units (up to seven in number) act as slaves. The master sends a data or POLL packet to poll a slave and the slave responds with a packet in the next time slot. The bandwidth of the piconet is divided among the slaves according to a polling algorithm used by the master. This polling algorithm has a significant impact on the system performance. In this paper, we propose a polling algorithm for Bluetooth that adapts to changes in traffic load and divides the piconet bandwidth among slaves in a max-min fair manner. We prove the fairness of the algorithm analytically and also verify it by simulations. We also show that the algorithm achieves a high efficiency in use of the piconet bandwidth.

Wireless Networks, 2010

Bluetooth is a short-range radio technology operating in the unlicensed industrial-scientific-medical (ISM) band at 2.45 GHz. A piconet is basically a collection of slaves controlled by a master. A scatternet, on the other hand, is established by linking several piconets together in an ad hoc fashion to yield a global wireless ad hoc network. This paper proposes a scheduling policy that aims to achieve increased system throughput and reduced packet delays while providing reasonably good fairness among all traffic flows in bluetooth piconets and scatternets. We propose a novel algorithm for scheduling slots to slaves for both piconets and scatternets using multi-layered parameterized policies. Our scheduling scheme works with real data and obtains an optimal feedback policy within prescribed parameterized classes of these by using an efficient two-timescale simultaneous perturbation stochastic approximation (SPSA) algorithm. We show the convergence of our algorithm to an optimal multi-layered policy. We also propose novel polling schemes for intra-and interpiconet scheduling that are seen to perform well. We present an extensive set of simulation results and performance comparisons with existing scheduling algorithms. Our results indicate that our proposed scheduling algorithm performs better overall on a wide range of experiments over the existing algorithms for both piconets (Das et al. in