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Analysis of Channel Access Priority Classes in LTE-LAA Spectrum Sharing System



Yao Ma


To provide differentiated quality of service (QoS) in long-term evolution (LTE) license assisted access (LAA) procedure, the 3GPP has defined several channel access priority classes (CAPCs), which use distinct arbitration inter-frame space (AIFS), contention window (CW) size, and payload duration. Though evaluating the effects of CW size and payload duration is relatively straightforward, accurately modelling and analyzing the effect of AIFS has not been satisfactorily addressed. Available methods on analyzing different AIFS's are limited to certain parameter setups, or involve systematic approximations. Different from existing results, we develop a non-homogeneous per-slot Markov chain model to represent state of each priority class during and after the AIFS, and analyze the channel access probability (CAP), successful transmission probability (STP), and average throughput of each class. Some novel features of our method include: 1. we model and solve the per-slot class-dependent link statistics (such as CAP and STP), which vary based on the slot location; and 2. we provide an in-depth analysis on the average throughput, for which we design a complicated multi-class combinatorial procedure to evaluate average time spent per successful transmission on each delay cell. We implement computer programming and extensive Monte Carlo simulations, which validate the accuracy of our analytical results, and demonstrate effects of AIFS and other parameters in an LAA system. These results provide a solid progress for evaluating priority classes in the LTE-LAA system and other spectrum sharing systems, and can be extended to support system and parameter optimization.
Proceedings Title
The 27th International Conference on Computer Communications and Networks (ICCCN 2018)
Conference Dates
July 30-August 2, 2018
Conference Location
Hangzhou, CN


Channel Access Priority Classes, CSMA/CA, LTE-LAA, QoS Differentiation, Spectrum Sharing, Throughput


Ma, Y. (2018), Analysis of Channel Access Priority Classes in LTE-LAA Spectrum Sharing System, The 27th International Conference on Computer Communications and Networks (ICCCN 2018), Hangzhou, CN, [online], (Accessed July 21, 2024)


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Created July 29, 2018, Updated April 13, 2022