Background and Motivation Our contributions Model the reading performance based on large experiments(240 tags, 90 tags per square meter) model the relationship between reading performance and reading power tag density Algorithm design to optimize performance based on the model
Background and Motivation Our Contributions • Model the reading performance based on – large experiments (240 tags, 90 tags per square meter) – model the relationship between reading performance and reading power & tag density • Algorithm design to optimize performance based on the model
Problem formulation ypical scenarIo: Continuous scanning in realistic settings, i.e., using a mobile reader to identify a large volume of tags deployed over a wide area The tags are continuously placed with a uniform or nonuniform density Performance metrics: Time efficiency Energy efficiency Coverage ratio
Problem Formulation • Typical scenario: – Continuous scanning in realistic settings, i.e., using a mobile reader to identify a large volume of tags deployed over a wide area. – The tags are continuously placed with a uniform or nonuniform density. • Performance metrics: – Time efficiency – Energy efficiency – Coverage ratio
Problem formulation Time-efficiency minimize t subject to E< energy constralnt PrC≥≥ coverage constraint Vti Es pi=p coverage constraint Energy-efficiency: minimize e subiect to T<Y time constraint PrC≥6≥ B coverage constraint Vt,Es Pi=p coverage constraint
Problem Formulation
Experiment Settings The rFid reader is statically dardosedhy ati gtscantenna teeuaresathe hgek-slgelf We set thaeistaneen认神却 恩科 dheareadmgB performance H t Ill A The tags used are Alien 9640 general-purpose tags Whusatteatthnghis Rfdso tag 是/1/a磨 brpicahenbisoksonHitloare paaa isdaistargt bookshelf. Tree spades dst composed of 12 grids with 4 columns and 3 rows
Experiment Settings We use the Alien-9900 reader and Alien-9611 linear antenna with a directional gain of 6dB. The tags used are Alien 9640 general-purpose tags. We attach the RFID tags onto the books which are placed in a large bookshelf. The bookshelf is composed of 12 grids with 4 columns and 3 rows. The RFID reader is statically deployed by facing its antenna towards the book shelf. We set the distance to 1.5m to guarantee the reading performance. This setting is close to a typical noisy condition, which is distinct from the free space condition