Stability Analysis of Frame Slotted Aloha Protocol

Abstract

Frame Slotted Aloha (FSA) protocol has been widely applied in Radio Frequency Identification (RFID) systems as the de facto standard in tag identification. However, very limited work has been done on the stability of FSA despite its fundamental importance both on the theoretical characterisation of FSA performance and its effective operation in practical systems. In order to bridge this gap, we devote this paper to investigating the stability properties of FSA by focusing on two physical layer models of practical importance, the models with single packet reception and multipacket reception capabilities. Technically, we model the FSA system backlog as a Markov chain with its states being backlog size at the beginning of each frame. The objective is to analyze the ergodicity of the Markov chain and demonstrate its properties in different regions, particularly the instability region. By employing drift analysis, we obtain the closed-form conditions for the stability of FSA and show that the stability region is maximised when the frame length equals the backlog size in the single packet reception model and when the ratio of the backlog size to frame length equals in order of magnitude the maximum multipacket reception capacity in the multipacket reception model. Furthermore, to characterise system behavior in the instability region, we mathematically demonstrate the existence of transience of the backlog Markov chain.

Stability of Synchronous Queued RFID Networks

“…FSA systems have VOLUME 7, 2019 stability issues when the tags contending and the number of slots in the FSA interrogation frame is unbalanced, causing either many collisions or many empty slots and thus inefficiency in the interrogation process. Some examples of works on this topic are [33]- [36] (see also references therein). Their goal is proposing and analyzing variations of the tag anti-collision protocol to achieve a constant (stable) performance.…”

“…Their goal is proposing and analyzing variations of the tag anti-collision protocol to achieve a constant (stable) performance. For example, Yu and Chen [33] discussed multiple and single packet reception p-persistent FSA protocols, Qian et al [34] proposed a scheme named ASAP to adaptively split the tag set into multiple subsets, estimating the cardinalities during the splitting to adapt the frame length. Jia et al [35] introduced a new anti-collision protocol named collision tree protocol (CT) and showed that it achieves constant time delay and power consumption for one-tag identification.…”

“…Besides, some works (e.g., [33], [37]- [39] have also studied the stability regions and schedulers for different types of RF-backscattering systems based on slotted aloha protocols. For example, the authors of [33] developed a model based on a discrete-time Markov chain, and through Lyapunov's drift analysis they proved the ergodicity of the chain. In [37], the authors analyzed the properties of slotted aloha with capture for random access over fading channels with infinitely-many users.…”

“…Earlier, Vogt [32] gave an approximation for this probability by obtaining the average interrogation frame duration experimentally. Other works (see [28], [33], and references therein) have proposed Markov chains to obtain this probability, where the stages correspond to interrogation frames/slots and assuming that the TDMA timeslot has a fixed number of these frames/slots. This method can be precise if they have similar durations, but in RFID durations depend on the event (singleton, idle or collision slot) and therefore Markov-based methods are inaccurate.…”

A multi-tag anti-collision protocol based on 8-ary adaptive pruning query tree

“…It is mainly categorized into two types: probabilistic anti-collision protocols based on Aloha 10,11 and deterministic anti-collision protocols based on trees. 12 The former includes slotted Aloha, 13 frame-slotted Aloha (FSA), 14 dynamic frameslotted Aloha (DFSA), 15 and so on. The latter contains binary search (BS) protocol, 16 query tree (QT) protocol, 17 collision tree (CT) protocol, 18 and so on.…”