This paper presents an efficient collision resolution protocol and its variations for the tag identification problem, where an electromagnetic reader attempts to obtain within its read range the unique ID number of each tag. The novelty of our main protocol is that each tag is memoryless, i.e., the current response of each tag only depends on the current query of the reader but not on the past history of the reader's queries. Moreover, the only computation required for each tag is to match its ID against the binary string in the query. Theoretical results in both time and communication complexities are derived to demonstrate the efficiency of our protocols.

We study contention-resolution protocols for multiple-access channels. We show that every backo protocol is transient if the arrival rate, , is at least 0.42 and that the capacity of every backo protocol is at most 0.42. Thus, we show that backo protocols have (provably) smaller capacity than full-sensing protocols. Finally, we show that the corresponding results, with the larger arrival bound of 0.531, also hold for every acknowledgement-based protocol.

Contention tree algorithms have provable stability properties, and are known to achieve stable throughput as high as 0.487 for the infinite population Poisson model. A common feature in all these random access protocols is that collided packets at the receive-node are always discarded. In this paper, we derive a novel tree algorithm (TA) that we naturally term SICTA because it relies on successive interference cancellation to resolve collided packets. Performance metrics including throughput and delay are analyzed to establish that SICTA outperforms existing contention tree algorithms reaching 0.693 in stable throughput. I.

Abstract—A novel random access protocol combining a tree algorithm (TA) with successive interference cancellation (SIC) has been introduced recently. To mitigate the deadlock problem of SICTA arising in error-prone wireless networks, we put forth a SICTA with first success (SICTA/FS) protocol, which is capable of high throughput while requiring limited-sensing and gaining robustness to errors relative to SICTA. Index Terms—Random access, successive interference cancellation (SIC), tree algorithm. I.

Random access is well motivated and has been widely applied when the network traffic is bursty and the expected throughput is not high. The main reason behind relatively low-throughput expectations is that collided packets are typically discarded. In this paper, we develop a novel protocol exploiting successive interference cancellation (SIC) in a tree algorithm (TA), where collided packets are reserved for reuse.

The throughput characteristics of a random access system (RAS) which uses Q-ary tree algorithms (where Q is the number of groups into which colliding users are split) of the Capetanakis–Tsybakov–Mikhailov–Vvedenskaya type are analyzed for an infinite population of identical users generating packets. In the standard model packets are assumed to be generated according to a Poisson process. In this paper we greatly relax this assumption and consider a rich class of Markovian arrival processes, which, in general, are non-renewal. This class of arrival processes is known to lend itself very well to modeling bursty and correlated arrival processes commonly arising in computer and communication applications. Blocked and grouped channel access protocols are considered in combination with Q-ary collision resolution algorithms that exploit either binary (“collision or not”) or ternary (“collision, success or idle”) feedback. For the resulting RASs the corresponding maximum stable throughput is determined. It is concluded that the resulting RASs maintain their good stability characteristics under the wide range of arrival processes considered, thereby further extending the theoretical foundations of tree algorithms.

Abstract — In this paper, we develop a random access scheme which combines the widely used binary exponential backoff (BEB) algorithm with a cross-layer tree algorithm (TA) that relies on successive interference cancellation (SIC) with first success (FS). BEB and SICTA/FS complement each other nicely in enabling the novel protocol to attain a maximum stable throughput (MST) as high as 0.6 without packet loss. Although BEB-SICTA/FS avoids the deadlock problem caused by the error propagation commonly present in successive interference cancellation (SIC) algorithms, it may still suffer from deadlock effects induced by the “level skipping ” caused by harsh wireless fading effects. We further develop a novel BEB-SICTA/F1 protocol, which is a modified version of BEB-SICTA/FS. Analysis and simulations demonstrate that this simple modification leads to high-throughput random access while completely avoiding deadlock problems. Index Terms — Random access, successive interference cancellation, tree algorithm, binary exponential backoff. I.

We study contention-resolution protocols for multiple-access channels. We show that every backo protocol is transient if the arrival rate, , is at least 0:42 and that the capacity of every backo protocol is at most 0:42. Thus, we show that backo protocols have (provably) smaller capacity than full-sensing protocols. Finally, we show that the corresponding results, with the larger arrival bound of 0:531, also hold for every acknowledgement-based protocol. 1 Introduction A multiple-access channel is a broadcast channel that allows multiple users to communicate with each other by sending messages onto the channel. If two or more users simultaneously send messages, then the messages interfere with each other (collide), and the messages are not transmitted successfully. The channel is not centrally controlled. Instead, the users use a contention-resolution protocol to resolve collisions. Thus, after a collision, each user involved in the collision waits a random amount of time (which i...

We consider random access in wireless networks under the physical interference model, wherein the receiver is capable of power-based capture, i.e., a packet can be decoded correctly in the presence of multiple transmissions if the received Signal to Interference and Noise Ratio exceeds a threshold. We propose a splitting algorithm that varies the transmission powers of users on the basis of quaternary channel feedback (idle, success, capture, collision). We show that our algorithm achieves a maximum stable throughput of 0.5518. Simulation results demonstrate that our algorithm achieves higher throughput and lower delay thanthat of the First Come First Servesplitting algorithmwith uniformtransmission power.

Abstract—The successive interference cancellation tree algorithm with first success (SICTA/FS) was specifically designed as a random access protocol over noisy collision channels. Given J users with an infinite buffer and subject to Poisson arrivals, SICTA/FS achieves throughputs as high as 0.6 if packet losses are allowed (up to 20%), while without packet losses its throughput quickly degrades as the number of users J increases. In this paper we indicate that SICTA/FS may remain stable for a considerable amount of time before becoming unstable when the arrival rate exceeds the maximum stable throughput. More importantly, we also study the ALOHA-SICTA/FS algorithm and show that it can achieve throughputs of 0.6 or above without packet loss. Additionally, we provide an accurate estimation of the mean packet delay under ALOHA-SICTA/FS using a simple queueing model with vacations. Finally, we indicate that ALOHA-SICTA/FS suffers from hardly any throughput reduction when the access point stores the last two collision signals only. Index Terms—Random access, tree algorithms, interference cancellation, SICTA/FS, ALOHA-SICTA/FS, AWGN channel I.