WSF_JTIDS_TERMINAL¶
- comm WSF_JTIDS_TERMINAL¶
comm <name-or-type> WSF_JTIDS_TERMINAL ... Platform Part Commands ... ... Articulated Part Commands ... ... Antenna Commands ... ... comm Commands ... ... transmitter ... end_transmitter ... receiver ... end_receiver ... WSF_JTIDS_TERMINAL Commands ... slot_group <group-name> ... WSF_JTIDS_TERMINAL Slot Group Commands ... end_slot_group relay_slot_group ... WSF_JTIDS_TERMINAL Slot Group Commands ... end_relay_slot_group end_comm
Overview¶
WSF_JTIDS_TERMINAL is an implementation that models the transport of data over a JTIDS network. It does not model either the message content or the pulse-level characteristics. The current implementation of the JTIDS terminal was derived mostly from reading Understanding Link-16; a Guidebook for New Users (Logicon, Inc.), NATO STANAG 5516. It models network capacity by requiring only the number of slots per frame needed by a slot group. It does not require (nor does it yet allow) a network definition via actual time slot block definitions (The current structure will allow it to be implemented at a future date). The model also allows changing of the basic network slot parameters (bits per slot, seconds per slot, slots per frame) to allow modeling of future concepts that may use the JTIDS TDMA architecture but with some modifications.
The current model implements:
multiple networks
per-slot-group packing limit
paired slot relays
dedicated access
time-slot reuse in relays (flood relays)
The model does not yet implement:
Contention access
Time slot reallocation access
Repromulgated relays
Note
This is NOT a Link-16 model - it doesn’t explicitly model the J-series messages. That is left to something higher up. This really just models the physical transport of a message.
Commands¶
- command_chain <command-chain-name> <slot-group-name>¶
Maps a command chain name to a slot group name, which allows platforms to form slot groups based on their command chain.
- maximum_range <length-value>¶
Defines the maximum range between the receiver and transmitter. This value will override any maximum_range explicitly defined in an antenna block. For JTIDS terminals, the Normal range is 300 nm and the Extended range is 500 nm. All JTIDS units in the same network should have identical range settings; however, this model does not enforce this restriction.
Default: 300 nautical miles
The remaining values are purely optional and are provided purely as a means to allow the simulation of future systems. These commands must be specified before any commands that create the slot groups.
- time_per_slot <time-value>¶
Overrides the amount of time per time slot.
Default: 7.8125 milliseconds
- slot_size <data-size-value>¶
Overrides the amount of data than can be contained in a slot (at the ‘normal’ packing density).
Default: 210 bits
- sets_per_frame <integer-value>¶
Overrides the number of interleaved sets per frame. Must be a value greater than zero.
Default: 3
- slots_per_set <integer-value>¶
Overrides the number of slots per set within a frame. Must be a value greater than one.
Default: 512
Slot Group Commands¶
- network <integer-value>¶
The JTIDS network number in the range [0, 127].
Default: 0
- tsec <integer-value>¶
The JTIDS cryptovariable specified for transmission security (TSEC) in the range [0, 127]. This model does not perform encryption/decryption of data. This value is used in Link-16 message headers.
Default: 0
- msec <integer-value>¶
The JTIDS cryptovariable specified for message security (MSEC) in the range [0, 127]. This model does not perform encryption/decryption of data. This value is used in Link-16 message headers.
Default: 0
- queue_limit <integer-value>¶
The maximum transmit queue size in the range [0, infinity].
Default: 99999
- packing_limit [standard | p2sp | p2dp | p4sp]¶
The packing format for messages, which affects the number of time slots needed to transmit a message. In Extended Range Mode (ERM) (i.e. a maximum range setting of 500 nm), a JTIDS terminal does not support the p2dp and p4sp packing structure. This model does not enforce this restriction.
standard: Standard double pulse ( 3x70 bits per time slot)
p2sp: Packed-2 single pulse ( 6x70 bits per time slot)
p2dp: Packed-2 double pulse ( 6x70 bits per time slot)
p4sp: Packed-4 single pulse (12x70 bits per time slot)
Default: standard
- relay_slot_offset <integer-value>¶
The offset of the paired relay slot group from the source slot group. The offset should be in the range of [1, infinity].
Note
The JTIDS protocol requires offsets to be in the range [5, 32].
Default: 6
- npg <integer-value>¶
The network participation group. The NPG may be either:
An integer between 1 and 511
One of the following: initial_entry, rtt_a, rtt_b, network_management, ppli_a, ppli_b, surveillance, weapons_coordination, air_control, electronic_warfare, unassigned, voice_a, voice_b, indirect_ppli, wc, fighter_to_fighter_dedicated, fighter_to_fighter_contention, engagement_coordination, joint_ppli, distributed_network_management, residual_message, ijms_position, ijms_message
Default: 0
Use the following three commands for a simplified way to allocate time slot blocks
- slots_per_frame <integer-value>¶
Slots per frame provides a simplified way to allocate TSBs. The number of slots per frame must in the range [1, terminal’s number of slots per frame].
Default: 1
- per_unit_slots_per_frame <integer-value>¶
The number of fractional slots that this slot group will use per frame.
Default: -1 (has no affect by default)
- receive_only¶
Indicates that this slot group can receive only.
Use the following two commands for an explicit way to allocate time slot blocks
- receive_slot_block <set>-<index>-<rrn>¶
Creates a receive slot block with the specified set (e.g., A, B, C), slot index, and recurrence rate number (RRN). The recurrence rate number must be in the range [1, 15].
- transmit_slot_block <set>-<index>-<rrn>¶
Creates a transmit slot block with the specified set (e.g., A, B, C), slot index, and recurrence rate number (RRN). The recurrence rate number must be in the range [1, 15].
