Wisent: Robust downstream communication and storage for computational RFIDs

Abstract

Computational RFID (CRFID) devices are emerging platforms that can enable perennial computation and sensing by eliminating the need for batteries. Although much research has been devoted to improving upstream (CRFID to RFID reader) communication rates, the opposite direction has so far been neglected, presumably due to the difficulty of guaranteeing fast and error-free transfer amidst frequent power interruptions of CRFID. With growing interest in the market where CRFIDs are forever-embedded in many structures, it is necessary for this void to be filled. Therefore, we propose Wisent-a robust downstream communication protocol for CRFIDs that operates on top of the legacy UHF RFID communication protocol: EPC C1G2. The novelty of Wisent is its ability to adaptively change the frame length sent by the reader, based on the length throttling mechanism, to minimize the transfer times at varying channel conditions. We present an implementation of Wisent for the WISP 5 and an off-the-shelf RFID reader. Our experiments show that Wisent allows transfer up to 16 times faster than a baseline, non-adaptive shortest frame case, i.e. single word length, at sub-meter distance. As a case study, we show how Wisent enables wireless CRFID reprogramming, demonstrating the world's first wirelessly reprogrammable (software defined) CRFID.c 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Alpaca: intermittent execution without checkpoints

“…Incidental computing [Ma et al 2017] and NEOFog [Ma et al 2018] optimize specific applications on top of the non-volatile processor. Wisent [Aantjes et al 2017;Tan et al 2016] addresses intermittence, but is not a computing model, instead enabling reliable software updating of in situ intermittent devices. Ekho [Zhang et al 2011b] helps test intermittent devices with support to collect and replay representative power traces from a realistic environment.…”

SecuCode: Intrinsic PUF Entangled Secure Wireless Code Dissemination for Computational RFID Devices

“…1 [14]). The data was generated from a CRFID device 50 cm away from a 9 dBic antenna energized by an Impinj R440 RFID Reader, as described in [12]. Addressing the research questions above require overcoming a number of challenges.…”

“…Notably, the firmware cannot generally be sent to the token T in a single transaction. The EPC Gen2 protocol implies a limitation on the length of a payload string to 255 words, which is inadequate to encapsulate a complete practical CRFID firmware [12]. Therefore, we partition the firmware input into n chunks {f irmware 0 , f irmware 1 , f irmware 2 , ..., f irmware n } and transmit sequentially indexed chunks {seq 0 , seq 1 , ..., seq n } to the token T using the BlockWrite command.…”

“…More recently, the Wisent method in Tan et al [12], R 2 and R 3 method in Wu et al [13], [15] demonstrated a robust wireless firmware update method for CRFID transponders using WISP platforms. In particular, R 3 was implemented on three different types of CRFID transponders.…”

“…More recently we have seen the emergence of tiny computing platforms in the form of highly resource constrained and intermittently powered batteryless devices that rely only on harvested RF energy for operations; best exemplified by Computational Radio Frequency Identification (CRFID) devices such as WISP [9], MOO [10] and commercial devices from Farsens [11]. The benefit of batteryless devices arises from: i) the removal of expensive or risky maintenance, for example, when devices are deeply embedded in reinforced concrete structures or tasked with blood glucose monitoring or pacemaker control [12]; ii) the reduction in the cost of devices; and iii) the potential for an indefinite operational life. However, a significant challenge materializes from the need to, specifically, patch, update or reprogram the application specific software in the form of firmware without the supervisory control of an operating system; to do so, a physical connection to a device is required.…”