Projects

Overview
Project Title	High Performance Reliability Protocol (HPRP)
Approval	Approved
Document Number
Charter	6.09 Delay Tolerant Networking Working Group
Document Type	Orange
Description of Document	The document specifies a protocol for reliable or unreliable delivery of blocks of data over space-to-ground, ground-to-space, and space-to-space links. Reliable delivery over less reliable links is achieved by an efficient segment-level re-transmission mechanism which makes the protocol suitable for highly asymmetrical data rates with large round-trip delays as experienced in inter-planetary communications while still being suitable for ultra-high-rate links with very small latencies. HPRP is designed for high-speed processing on typical flight hardware including FPGA and ASIC, as well as providing standard user interface semantics for all transmission modes. While HPRP protocol is an evolution of the CCSDS Licklider Transmission Protocol and shares some of the concept, it is not backward compatible. As it is also covering the same use cases, it is expected that the new protocol could replace the use of LTP in the future.
Applicable Patents	There are no patent issues for this technology that are known by the CCSDS community
Patent Comments
Survey of Similar Standards Documents or Projects Undertaken in Other Bodies and elsewhere in CCSDS	The proposed protocol is an evolution of the CCSDS LTP protocol which includes the use of self-delimiting numeric values (SDNVs) in some of the protocol fields. While this allows LTP to maintain bit efficiency over a wide range of operational environments (e.g. when sending different sized LTP blocks), it results in headers where the size MAY vary from segment to segment and that require parsing multiple SDNVs. This makes it difficult to implement LTP in high-speed environment or extremely resource-constrained environments where the LTP processing is moved to field programmable gate arrays (FPGAs) or other hardware accelerators. A recent ESA study performed by GMV (with contributions from DLR) analysed a variety of space and terrestrial protocols (TCP, QUIC, SCPS-TP, SRT, NORM, LTP, CFDP, COP-1/-P, 802.11 BA, AX.25) in terms of required capabilities and suitability for hardware implementations and concluded that the definition of a new protocol based on LTP is the most suitable way forward.
Resources
Book Editor	DLR
Book Editor Resources	1
Prototype 1	DLR
Prototype 1 Resources	1
Prototype 2
Prototype 2 Resources
Prototype 3
Prototype 3 Resources
Contribute	ESA
Monitor Only	NASA
Resource Comments	2 prototypic implementation (software and FPGA) are already available at DLR and have been extensively tested.

Schedule

Legend for Schedule Milestones = Required for Orange Books = Required for Green Books = Required for Magenta Books = Required for Blue Books Note - Red Books are Draft Blue/Magenta Books Schedule Milestones	Original Completion Date (Date in M/D/YYYY format.)	Comments (Date in M/D/YYYY format.)
Project Approved	11/1/2023
Project Start Date	11/6/2023
Internal WG Review
First Draft Circulated to WG	1/31/2024
First Draft Comments Due	2/29/2024
Second draft circulated to WG	4/30/2024
Second Draft Comments Due	5/31/2024
Final WB Submitted to AD for Further Processing	6/28/2024
External Milestones
Secretariat Document Processing	8/30/2024
First Agency Review
RID Resolution
Secretariat Document Processing 2
Final Agency Review
RID Resolution
First Prototype Development
Second Prototype Development
CMC Approval	10/31/2024
Total Time to Complete (in months)	12