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

Quality of Service over Specific Link Layers: state of the art report

The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service

Intra-piconet scheduling in Bluetooth

The trend of dynamically interconnecting the personal devices that people carry with them has led to the introduction of personal area networks (PANs) and personal networks (PNs). The Bluetooth® wireless access technology is believed to be a potential enabler of PANs and PNs. This dissertation focuses on Bluetooth intra-piconet scheduling (also referred to as Bluetooth polling) that helps in making the Bluetooth technology a successful enabler of PANs and PNs. In order for the Bluetooth technology to be such a successful enabler, its polling mechanism should be efficient. At the same time, the polling mechanism should also be fair. Finally, the polling mechanism must be able to provide quality of service (QoS), which is needed to support audio and video applications. Conventional polling mechanisms are less suitable for Bluetooth as they do not take the Bluetooth specification into account. Current Bluetooth polling mechanisms are either not able to poll in a fair and efficient manner, or they do not provide the needed QoS. In this thesis, a new polling mechanism, named Predictive Fair Poller (PFP), is developed. This polling mechanism predicts the availability of data for each slave, and it keeps track of fairness. Based on these two aspects, it decides which slave to poll next such that the effi- ciency and fairness are optimized. Further, two new QoS-capable polling mechanisms are developed, namely the fixed-interval poller and the variable-interval poller. These pollers follow the IETF s Guaranteed Service approach, hence providing both a rate guarantee and a delay guarantee. With respect to Bluetooth polling, this is new. The fixed-interval poller plans polls to slaves with fixed intervals, whereas the variable-interval poller postpones polls for slaves, whenever possible, in order to save bandwidth. The fixed-interval poller and the variable-interval poller provide, with some predefined maximum deviation, a rate guarantee, which leads to a delay guarantee, provided that the traffic sources comply to their traffic flow specification. These two types of guarantees are the main QoS types that are needed for audio and video applications. Additionally, retransmission strategies are developed that minimize the influence of bad radio environments on the provisioning of these QoS types. The mechanisms and techniques developed in this work are evaluated by means of simulation studies. These studies show that PFP is fair and efficient. In particular, the studies show that PFP performs at least as good as and sometimes better than existing Bluetooth polling mechanisms. Furthermore, the studies show that the variable-interval poller outperforms the fixed-interval poller, and that it is able to guarantee delay bounds that approach the delay bounds that can be guaranteed using a synchronous connection-oriented (SCO) channel. Moreover, the variable-interval poller is able to do so while consuming less resources. As the variable-interval poller can also perform retransmissions, this saved bandwidth can be used to avoid the link quality problems of SCO channels in bad radio environments, while keeping up QoS

Providing QoS 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 retransmissions

Predictive fair polling mechanism in a wireless access scheme

Method and system for controlling access to a communication channel. The method involves calculating an efficiency value for each communication device of a plurality of communication devices, calculating a fairness value for each communication device of the plurality of communication devices, and providing each of the plurality of communication devices with access to the communication channel based on a result of the calculations. The methods considers both efficiency and fairness in deciding which of the plurality of communication devices to select thus providing a system designer with the ability to achieve a good compromise between efficiency and fairness. The system includes a slave tracker within a master communication device for performing the calculations and for deciding which of the plurality of slave communication device to give access to the communication channel

Polling Best Effort Traffic in Bluetooth

Bluetooth is a wireless access technology where polling is used to share bandwidth among the nodes. We have introduced a new Poller named Predictive Fair Poller (PFP). We explain the operation of the Predictive Fair Poller and compare it with the conventional Round Robin Poller and the Fair Exhaustive Poller (FEP) for two Best Effort traffic scenarios. We show through simulations that the Predictive Fair Poller is able to divide bandwidth in a fair and efficient manner

Polling in Bluetooth: a simplified best effort case

Bluetooth [1] is a wireless access mechanism where polling is used to share bandwidth among the participants. We introduce a new poller named Predictive Fair Poller [2] (PFP). We compare this poller with the conventional Round Robin poller and the Fair Exhaustive Poller [4] and show through simulations that the Predictive Fair Poller is able to divide bandwidth in a fair and efficient manner. 1