Improving Information Freshness via Backbone-Assisted Cooperative Access Points

Pan，Haoyuan1; Zhou，Yu1; Chan，Tse Tin2; Tang，Ming3; Li，Jianqiang1; Du，Zhihua1

2022

10.1109/JIOT.2022.3218948

IEEE Internet of Things Journal   Impact Factor & Quartile

2372-2541

2327-4662

Information freshness, characterized by age of information (AoI), is important for sensor applications involving timely status updates. In many cases, the wireless signals from one sensor can be received by multiple access points (APs). This paper investigates the average AoI for cooperative APs, in which they can share information through a wired backbone network. We first study a basic backbone-assisted COoperative AP (Co-AP) system where APs share only decoded packets. Experimental results on software-defined radios (SDR) indicate that Co-AP significantly improves the average AoI performance over a single-AP system. Next, we investigate an improved Co-AP system, called Soft-Co-AP. In addition to sharing decoded packets, Soft-Co-AP shares and collects soft information of packets that the APs fail to decode for further joint decoding. A critical issue in Soft-Co-AP is determining the number of quantization bits that represent the soft information (each soft bit) shared over the backbone. While more quantization bits per soft bit improves the joint decoding performance, it leads to higher backbone delay. We experimentally study the average AoI of Soft-Co-AP by evaluating the tradeoff between the backbone delay and the number of quantization bits. SDR experiments show that when the number of sensors is large, Soft-Co-AP further reduces the average AoI by 12% compared with Co-AP. Interestingly, good average AoI performance is usually achieved when the number of quantization bits per soft bit is neither too large nor too small.

Age of information (AoI) backbone Decoding Delays information freshness Internet of Things Quantization (signal) Smart cities soft bits Symbols Time division multiple access

EI ; SCI

English

Others

National Natural Science Foundation of China["62001298","62176164","62073225","62203134","62202214"] ; Guangdong Pearl River Talent Recruitment Program[2019ZT08X603] ; Guangdong Pearl River Talent Plan[2019JC01X235] ; Natural Science Foundation of Guangdong Province-Outstanding Youth Program[2019B151502018] ; Guangdong Basic and Applied Basic Research Foundation[2021A1515012601] ; Shenzhen Science and Technology Program[RCBS20210609103234060] ; Shenzhen Science and Technology Innovation Commission[R2020A045] ; Faculty Development Scheme from the Research Grants Council of Hong Kong[UGC/FDS14/E02/21]

Computer Science ; Engineering ; Telecommunications

Computer Science, Information Systems ; Engineering, Electrical & Electronic ; Telecommunications

WOS:000938278700063

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

20224613110218

Decoding ; Quantization (signal) ; Smart city ; Software radio ; Stabilization ; Time division multiple access

Modulators, Demodulators, Limiters, Discriminators, Mixers:713.3 ; Radio Systems and Equipment:716.3 ; Data Communication, Equipment and Techniques:722.3 ; Computer Software, Data Handling and Applications:723 ; Data Processing and Image Processing:723.2

2-s2.0-85141560646

Scopus

1.College of Computer Science and Software Engineering, Shenzhen University, Shenzhen, China
2.Department of Mathematics and Information Technology, The Education University of Hong Kong, Hong Kong, China
3.Department of Computer Science and Engineering in Southern University of Science and Technology, Shenzhen, China

Pan，Haoyuan,Zhou，Yu,Chan，Tse Tin,et al. Improving Information Freshness via Backbone-Assisted Cooperative Access Points[J]. IEEE Internet of Things Journal,2022,PP(99):1-1.

Pan，Haoyuan,Zhou，Yu,Chan，Tse Tin,Tang，Ming,Li，Jianqiang,&Du，Zhihua.(2022).Improving Information Freshness via Backbone-Assisted Cooperative Access Points.IEEE Internet of Things Journal,PP(99),1-1.

Pan，Haoyuan,et al."Improving Information Freshness via Backbone-Assisted Cooperative Access Points".IEEE Internet of Things Journal PP.99(2022):1-1.