Analog Bloom Filters for Wireless Control: From Cellular Random Access to Scalable LoRa Acknowledgment
Zhenghao Zhang · Computer Science Colloquium Series
| Speaker | Zhenghao Zhang |
| Date | Friday, August 28, 2:15 – 3:05 pm |
| Location | 307 Love |
Abstract
Wireless control often asks a simple but difficult question: which users are active, requesting resources, or acknowledged? Existing systems usually answer this question with packet bits, dedicated resources, or one sequence per user, which becomes inefficient when many low-power devices share limited wireless resources. This talk presents Analog Bloom Filter (ABF), a physical-layer approach inspired by the Bloom filter that moves probabilistic membership testing into the wireless signal itself. The first part of the talk introduces ABF through cellular access. In ABF PRACH, a user transmits a pattern of multiple Zadoff-Chu sequences instead of selecting a single random-access sequence, greatly reducing collision probability. The second part presents ABF_PACK, which reverses the direction of ABF for LoRa networks. The gateway broadcasts an analog membership signal containing multiple peaks that allows each node to determine whether its uplink packet was acknowledged by checking the existence of peaks.
About the speaker
Zhenghao Zhang received his B.Eng. and M.S. degrees in Electrical Engineering from Zhejiang University, Hangzhou, China, in 1996 and 1999, respectively, and his Ph.D. in Electrical Engineering from the State University of New York at Stony Brook in 2006. From 1999 to 2001, he worked in industry as an embedded systems software engineer. He was a Postdoctoral Researcher in the Computer Science Department at Carnegie Mellon University from 2006 to 2007. He joined the Department of Computer Science at Florida State University in Fall 2007, where he is currently a Full Professor. His primary research interest is wireless networks. He has published papers in highly reputable venues, such as ACM Sensys, IEEE Infocom, ACM CoNEXT, ACM Mobihoc, ACM Mobisys, IEEE ICNP, IEEE/ACM Transactions on Networking, and IEEE Transactions on Wireless Communications. His research group is familiar with SDR and has extensive experience with the POWDER platform. He has shared with the community both code and data sets in multiple projects, including a software LoRa receiver, a software LR-FHSS receiver, and software to analyze Starlink satellite beacons.