Hello,
Some useful scribbles as programs decoding IDAS become available.
The Icom IDAS Trunk System is an all digital form of an enhanced LTR system. There is no defined control channel and a slow rate data steam (SACH) is used for control information. Much of the same terminology and trunking techniques of an enhanced LTR system apply to an IDAS system.
IDAS is defined in Parts 1-E and 1-F of the NXDN Technical Specifications. There are some differences between the over-the-air data (CAI) between IDAS defined in Part 1-E and NexEdge/Conventional defined in Part 1-A. Very dry reading.
There are three types of systems possible with IDAS, a single site system, a multisite system linking mutiple sites together, and a intersystem system linking multiple mutisite systems together.
The System ID is split between an Intergrator Code (0 to 15) and System Code (0 to 32767) with 1-1 being a default value.
Site Ids have a range of 1 to 250 with reserved values of 0 and 251 to 255.
A LTR style Area bit is used in place of the Radio Access Number (RAN).
LTR style Repeater numbers are used with a range of 1 to 30. 0 and 31 are used for special purposes, like indicating end of transmission, or all repeaters are busy.
LTR style radio ids are used with the home repeater portion replaced by a subgroup prefix with a range of 1 to 30. This is tied to a home repeater on single site systems. The prefix of 0 is used as a filler or to indicate a user from another system on a intersystem system. The group portion has a range of 1 to 2000 for normal groups with 0 used as a filler. 2047 is used to indicate all groups and 2001 to 2046 are used for special ids and purposes.
A home repeater will send a burst of data every 2 seconds or so. It is quite sparse on a single site system with just an Idle message. A site in a multisite and intersystem system will send the Site Id and Adjacent Site information.
A multisite and intersystem site will also have a collect repeater that will send a burst of data every 2 seconds or so. The main traffic on the collect repeater will be registration of radios as they roam between sites. Voice traffic can be carried on the collect repeater if all the other repeaters at the site are busy.
73 Eric
Some useful scribbles as programs decoding IDAS become available.
The Icom IDAS Trunk System is an all digital form of an enhanced LTR system. There is no defined control channel and a slow rate data steam (SACH) is used for control information. Much of the same terminology and trunking techniques of an enhanced LTR system apply to an IDAS system.
IDAS is defined in Parts 1-E and 1-F of the NXDN Technical Specifications. There are some differences between the over-the-air data (CAI) between IDAS defined in Part 1-E and NexEdge/Conventional defined in Part 1-A. Very dry reading.
There are three types of systems possible with IDAS, a single site system, a multisite system linking mutiple sites together, and a intersystem system linking multiple mutisite systems together.
The System ID is split between an Intergrator Code (0 to 15) and System Code (0 to 32767) with 1-1 being a default value.
Site Ids have a range of 1 to 250 with reserved values of 0 and 251 to 255.
A LTR style Area bit is used in place of the Radio Access Number (RAN).
LTR style Repeater numbers are used with a range of 1 to 30. 0 and 31 are used for special purposes, like indicating end of transmission, or all repeaters are busy.
LTR style radio ids are used with the home repeater portion replaced by a subgroup prefix with a range of 1 to 30. This is tied to a home repeater on single site systems. The prefix of 0 is used as a filler or to indicate a user from another system on a intersystem system. The group portion has a range of 1 to 2000 for normal groups with 0 used as a filler. 2047 is used to indicate all groups and 2001 to 2046 are used for special ids and purposes.
A home repeater will send a burst of data every 2 seconds or so. It is quite sparse on a single site system with just an Idle message. A site in a multisite and intersystem system will send the Site Id and Adjacent Site information.
A multisite and intersystem site will also have a collect repeater that will send a burst of data every 2 seconds or so. The main traffic on the collect repeater will be registration of radios as they roam between sites. Voice traffic can be carried on the collect repeater if all the other repeaters at the site are busy.
73 Eric