Ericsson LBI-38965B Overview, Billing by Conversation, Billing for Multiple Sites

LBI-38965 EDACS BILLING FORMAT

This appendix defines the EDACS call detail record (CDR) format for the collection of system resource usage data in a multisite trunked radio system. The document is intended for use primarily by air time billing software developers who use this record format as input, as well as for developers of equipment and software to collect and archive call detail data from

EDACS.

1. OVERVIEW

The EDACS CDR is designed to record call activity on an EDACS multisite trunked radio system. The records are intended primarily for billing purposes. The EDACS CDR format balances efficient storage with comprehensive resource utilization data.

2. BILLING BY CONVERSATION

EDACS uses transmission trunking to allocate RF channels. Unlike a landline telephone conversation, where a single circuit is established at the beginning of the call and disconnected at the end, EDACS establishes a new "circuit" (assigns an RF channel) each time a conversation participant presses the PTT switch on a radio, and disconnects (drops the channel) as soon as the PTT switch is released. Thus, a single conversation may result in several RF channel assignments. Rather than designate each of these brief transmissions as a call requiring its own CDR, the EDACS CDR format permits all of the transmissions making up a single conversation to be recorded in a single CDR. The CDR records the elapsed time of the conversation, the actual accumulated air time (time that an RF channel was in use) and the number of transmissions involved. A list of the channels used in the call is also part of the record.

3. BILLING FOR MULTIPLE SITES

EDACS allows calls which originate on one radio site and use RF channels on one or more additional sites. The EDACS CDR format accommodates these calls by recording the site number and a list of the RF channels used for each site participating in the call. In addition , the accumulated air time field in the CDR contains the total air time used on all sites. In this case, the accumulated air time value will usually be greater than the elapsed time.

4. RECORD ENCODING

An EDACS CDR is an ASCII text record terminated by a linefeed character (LF, decimal 10). The record consists of fixed length fields. The total number of fields in the record is variable, depending on whether the call involved multiple sites or was a radio-originated telephone interconnect call.

Most of the fields are numeric data and are specified as either Decimal or Hex format. Decimal format fields are radix- 10 integers encoded using the ASCII characters from decimal 48 (“0”) through decimal 57 (“9”). Hex fields are radix-16 integers encoded using the ASCII characters from decimal 48 (“0”) through decimal 57 (“9”) and decimal 65 (“A”) through decimal 70 (“F”). Two additional formats are used. The radix-64 format is used to provide a sequence number for each record. The last format used is the dialed digits format. This format is used to record a telephone number dialed by the originator of a mobile-to-land telephone interconnect call. The standard digits on a telephone DTMF keypad are encoded using the ASCII characters decimal 35 (“#”), decimal 42 (“*”), and decimal 48 (“0”) through decimal 57 (“9”).

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