A Just-In-Time Networking Framework for Minimizing Request-Response Latency of Wireless Time-Sensitive Applications

TL;DR

This paper introduces a just-in-time (JIT) networking framework designed to minimize request-response latency in wireless time-sensitive applications by synchronizing client requests and server transmissions with network opportunities.

Contribution

The paper proposes a novel JIT communication paradigm, including a protocol stack implementation over TDMA, and proves the optimality of power-of-2 time slots for server-side JIT in SoC networks.

Findings

JIT networks significantly reduce request-response latency.

The TDMA-based JIT system outperforms traditional approaches.

Optimality of power-of-2 time slots for server JIT is demonstrated.

Abstract

This paper puts forth a networking paradigm, referred to as just-in-time (JIT) communication, to support client-server applications with stringent request-response latency requirement. Of interest is not just the round-trip delay of the network, but the actual request-response latency experienced by the application. The JIT framework contains two salient features. At the client side, the communication layer will 'pull' a request from the client just when there is an upcoming transmission opportunity from the network. This ensures that the request contains information that is as fresh as possible (e.g., a sensor reading obtained just before the transmission opportunity). At the server side, the network ascertains that the server, after receiving and processing the request to generate a response (e.g., a control command to be sent to the client), will have a transmission opportunity at just this time. We realize the JIT system, including the protocol stack, over a Time-Division-Multiple-Access (TDMA) network implemented on a System-on-Chip (SoC) platform. We prove that a TDMA network with a power-of-2 time slots per superframe is optimal for realizing the server-side JIT function. Our experimental results validate that JIT networks can yield significantly lower request-response latency than networks without JIT support can.