Null - Ping and Padding Layer (00h)

OSI: Transport Layer

Keywords: keep-alive, padding in framing, encapsulation, low communication overhead, sensors, internet of things, embedded systems, sensor networks

Scope

The scope of this project is to define the Isotropic Sensor Network User layers for broadcast and peer to peer connection in distributed sensor area network, wired or wireless, low and high data rate devices, battery powered devices, short-range devices with short operational space, low-cost devices to support trivial sensors, besides the fully featured devices.

Purpose

The purpose of this specifications is to provide a standard for low complexity, low cost, and low power (aware) consumption devices (sensors) to provide keep alive capability and padding for frame and packet alignment.

Definitions, Acronyms and Abbreviations

device

An entity containing this protocol implementation. Also referred as sensor device or just sensor or device.

frame

The format of aggregated bits that are transmitted together in time.

packet

The format of aggregated bits that are transmitted together in time across the physical medium.

Packet Format

Fields

Protocol ID

Bits

8

Value

00h

Protocol ID:

defines the unique protocol identification number of the application protocol specific format

Keep alive

In many cases the underlying media cannot provide information whether a device is alive or not, or looking from a device side, whether host (peer) is connected or does it exist.

The device and host should thus support keep-alive capability in which, after reception of the packet with Null protocol only, then the queried device should respond either with some valid message or Null.

Padding

Some devices may due to internal optimization require padding bytes to align data structure to i.e. 32-bit boundaries. And in other cases packets may need to be filled to account a fixed size. In such cases the Null is used as a padding byte.

Document Changes

Date

Release

Changes

September 15, 2018

1.0

Initial Specifications

References