The Joint Range Extension Application Protocol (JREAP) enables tactical data to be transmitted over digital media and networks not originally designed for tactical data exchange.
Formatted tactical digital messages are embedded inside of JREAP messages as data fields within available commercial and Government protocols, such as those used over satellites and terrestrial links.
Specialized management messages are also provided to transport data not contained in the formatted messages, in order to support TDL-unique functions.
Capabilities are provided that include:
- Extending the range-limited tactical networks to beyond LOS while reducing their dependence upon relay platforms,
- Reducing the loading on stressed networks,
- Providing backup communications in the event of the loss of the normal link,
- Providing a connection to a platform that may not be equipped with the specialized communications equipment for that TDL.
For media that do not support OSI network and transport layers, the JREAP provides network and transport layer functionality. For media supporting OSI network and transport layers, the JREAP is encapsulated within those layers. JREAP software can be integrated into a host system or into a stand-alone processor. The appropriate interface terminals are required at each end of any JREAP alternate media link.
JREAP appendix A: Half-Duplex Announced Token Passing Protocol
This protocol may be used when several terminals share the same JRE media and take turns transmitting, or, in a broadcast situation, when one transmits and the rest receive. It is targeted to data rates down to 2400 bits per second (bps) on a serial data interface with a TSEC/KG-84A/KIV-7 or a compatible encryption device used for data security. It is designed for use with media such as: 25-kHz UHF TDMA/DAMA SATCOM (MIL-STD-188-183), EHF LDR Forced Mode Network Operations (MIL-STD-188-1582), and 5- and 25-kHz UHF non-DAMA SATCOM (MIL-STD-188-181).
This Token Passing version of the JREAP addresses the following basic timing and communication requirements:
- The maximum time between Link 16 data element updates should not exceed 20 seconds.
- The link latency should not exceed 12 seconds.
- The protocol supports extrapolation of time sensitive data.
- The Network Time Reference (NTR) should include the time error for estimating when the transmission sync bits leave the physical interface when determining time accuracy.
- The protocol should support both operations within 25-kHz UHF DAMA and EHF LDR equipment limitations, using the Full Stack mode of operation (see 5.4).
- Two bytes of marks shall be transmitted prior to the sync characters. These marking bytes allow the sync characters to be received if any bits are dropped during the communication initialization process.
JREAP appendix B: Full-Duplex Synchronous or Asynchronous Point-to-Point Connection
SHF SATCOM links typically experience a high data bit error rate, relative to other media. Since commercial data link layer protocols expect a low bit error rate, they routinely discard entire data frames with single bit errors. This appendix defines an application-layer- type protocol that includes link layer-style error detection in place of the lower level protocols, in order to salvage as much data as possible from corrupted packets.
JREAP appendix C: Encapsulation over Internet Protocol (IP)
The Internet Protocol Suite is a standard set of protocols that is deployed worldwide in commercial as well as military networks. By using JREAP encapsulation over IP, JRE can be performed over IP-based networks that meet operational requirements for security, speed of service, and so on.
Since TCP IP and UDP IP data are either delivered intact or not delivered at all, the JREAP application layer does not provide for recovery of corrupted messages.
The JREAP is independent of the version of IP that is used. Early implementations will use IP version 4 (IPv4), and implementers should consider IP compatibility issues when moving to future IP versions.
The Joint Range Extension Application Protocol (JREAP) enables tactical data to be transmitted over digital media and networks such as satellite communications systems. The tactical digital messages are embedded in JREAP messages as data fields, and additional specialized management messages are also provided to transport data not contained in the formatted messages.
The are three ways to use JRE as a Gateway (GW) : Inter-Zone, Intra-Zone and Reach-Back/Reach-Forward.
Exchange of tactical data between two or more faraway Tactical Data Links Networks Area.
Exchange of tactical data inside one extended range Tactical Data Links Networks Area, to resolve the problem of LOS (especially in LINK 16 extended rage networks on a large area).
Relay the tactical data BLOS back to a C2 land-based or maritime battle-staff, or forward a C2 advanced unit.