Transport Layer (7Eh) and (7Dh)

Isotropic Sensor Network Specifications, Transport Layer

OSI: Transport Layer

Keywords: Connection/-less network, flow control, reliable transport service, low communication overhead, sensors, internet of things, embedded systems, sensor networks

Document: ISN-Transport-1.x released on September 15, 2018 by Isotel, (c) All Rights Reserved

Creative Commons License
Isotropic Network Specifications: Transport Layer 1.x by Isotel is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.
Permissions beyond the scope of this license may be available at http://isotel.net/ref/ISN-Permissions.

Note: Any adaptations to this specifications made by groups, individuals or companies are according to the license not allowed for general publication, but we strongly encourage you to send your modifications back to us for further consideration for the next releases.

Scope

The scope of this project is to define the Isotropic Sensor Network Transport layer 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 a connection-less and reliable connection-oriented network in combination with a Sensor Frame layer.

Key features

  • Adds Logical Ports and Sequence Counters
  • Basic Hand-Shaking
  • Low-Cost and Compact Implementation

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.
LSB
least significant byte/bit
MSB
most significant byte/bit

Packet Formats

Protocol defines short and long frame formats:

  • short frame format supports connection-less network, with up to 64 logic ports and 2 pending transactions
  • long frame format supports connection-oriented network, with up to 256 logic ports, 8 pending transactions, and flow-control acknowledge bits

Both protocol can be nested to address larger space and more complex structures.

Short Frame Format (16-bits)

Fields Protocol ID Port Counter Payload
Bits 8 6 2 N
Value 0x7E 0-63 0-3 user
Protocol ID:
defines the unique protocol identification number
Port:
logical port 0..31
Counter:
packet counter 0..3
User Payload:
of arbitrary length, typically defined by upper or nested Frame Layer (80h+)

Long Frame Format (24-bits)

Extends the Short Frame format and adds optional hand-shaking with two acknowledge bits.

Fields Protocol ID Port Counter Ack Payload
Bits 8 8 14 2 N
Value 0x7D 0-255 0-16383
user
Protocol ID:
defines the unique protocol identification number
Port:
logical port 0..255
Counter:
packet counter 0..16383
User Payload:
of arbitrary length, typically defined by upper or nested Frame Layer

Opening and Closing Port

Opening a port starts with a first message from or to selected port and non-empty message.

Any side may close the port by sending an empty message, a message which does not contain any user payload.

Packet Counter

In general counter is incremented after every transmission of a packet,

Acknowledge Bits

To be revised.

Document Changes

Date Release Changes
January 17, 2015
Initial specifications.
February 21, 2016 1.0 Public version of Renewed Sensor Transport Layer
September 15, 2018 1.x Reviewing in progress

References

Disclaimer

Use of an ISOTEL specification is wholly voluntary. The ISOTEL disclaims liability for any personal injury, property or other damage, of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or reliance upon this, or any other ISOTEL specification document.

The ISOTEL does not warrant or represent the accuracy or content of the material contained herein, and expressly disclaims any express or implied warranty, including any implied warranty of merchantability or fitness for a specific purpose, or that the use of the material contained herein is free from patent infringement. ISOTEL specifications documents are supplied AS IS.

The existence of an ISOTEL specification does not imply that there are no other ways to produce, test, measure, purchase, market, or provide other goods and services related to the scope of the ISOTEL specification. Furthermore, the viewpoint expressed at the time a specification is approved and issued is subject to change brought about through developments in the state of the art and comments received from users of the specification. Every ISOTEL specification is subjected to review at least every five years for revision or reaffirmation. When a document is more than five years old and has not been reaffirmed, it is reasonable to conclude that its contents, although still of some value, do not wholly reflect the present state of the art. Users are cautioned to check to determine that they have the latest edition of any ISOTEL specification.

In publishing and making this document available, the ISOTEL is not suggesting or rendering professional or other services for, or on behalf of, any person or entity. Nor is the ISOTEL undertaking to perform any duty owed by any other person or entity to another. Any person utilizing this, and any other ISOTEL specifications document, should rely upon the advice of a competent professional in determining the exercise of reasonable care in any given circumstances.

Interpretations: Occasionally questions may arise regarding the meaning of portions of specifications as they relate to specific applications. When the need for interpretations is brought to the attention of ISOTEL, the ISOTEL will initiate action to prepare appropriate responses. Since ISOTEL specifications represent a consensus of concerned interests, it is important to ensure that any interpretation has also received the concurrence of a balance of interests. For this reason, ISOTEL and the members of its societies are not able to provide an instant response to interpretation requests except in those cases where the matter has previously received formal consideration.

Comments for revision of ISOTEL specifications are welcome from any interested party, regardless of membership affiliation with ISOTEL. Suggestions for changes in documents should be in the form of a proposed change of text, together with appropriate supporting comments. Comments on specifications and requests for interpretations should be addressed to Isotel d.o.o., Slovenia.

Attention is called to the possibility that implementation of this specification may require use of subject matter covered by patent rights. By publication of this specification, no position is taken with respect to the existence or validity of any patent rights in connection therewith. The ISOTEL shall not be responsible for identifying patents for which a license may be required by an ISOTEL specification or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention.