Background

. Behavior Engineering

. Software Change

. Software Tools

. Microwave Oven Case Study

. Satellite Control System

Mircowave Oven Case Study

Version 1

. Requirements and RBT

. The DBT

. Other Design Diagrams

Version 2 and 3

. Version 2

. Version 3

Evolutionary Diagrams

. EVDBT for version 1,2 and 3

. Other Evolutionary Diagrams

Satellite Control System

Requirements and RBTs

. Requirement 2.1

. Requirement 2.2

. Requirement 2.2.1

. Requirement 2.2.2

. Requirement 2.2.3

. Requirement 2.3

. Requirement 2.3.1

. Requirement 2.3.2

. Requirement 2.3.3

. Requirement 2.3.4

. Requirement 2.3.5

. Design Behavior Tree

Other Versions

. Version 2 Requirement 2.2.3

. DBT for Version 2

. Version 3 Requirement 2.1

. DBT for Version 3

. Version 4 Requirement 2.2.2

. DBT for Version 4

. Version 5 Requirement 2.3.4

. DBT for Version 5

. The Evolutionary DBT

2.3.1 Establishing an Uplink/Downlink Site-SCS Connection

Once a maintenance time slot is ended, the SCS is ready to receive "Transmit Data" transaction command and acknowledgment messages from the GCS, the uplink site, and the downlink site.

TG1) A TG command message shall specify the (1) the uplink site ID, (2) the downlink site ID, and (3) the planned time slot duration.

TG2) The SCS shall receive a TG (customer data transmission time slot go) command message from the GCS. That signals the initiation of a "Transmit Data" transaction for a specified customer data transmission time slot.

The current "Manage Satellites" transaction shall be terminated when the SCS receives a TG command message.

TG3) The SCS shall look up the entries for the uplink and downlink sites in the B/L lookup table that are specified in the TG command message.

TG3.1) If uplink and downlink site entries are found in the B/L table, the SCS shall forward the TG command message to the uplink site and the downlink sites identified in the TG command message.

TG3.2) If an uplink and/or a downlink site entry is not found in the B/L table, the SCS shall prepare and return a TSCAN (time slot canceled) acknowledgment message to the GCS with (1) a status code of 2 if the uplink site entry is not found, (2) a status code of 3 if the downlink site entry is not found, or (3) a status code of 4 if neither site entry is found.

Report Site Readiness

UG1) The SCS shall receive a UG (uplink good) acknowledgment message if the uplink site is ready to send data.

UG2) A UG may only be received during a valid "Transmit Data" transaction.

DG1) The SCS shall receive a DG (downlink good) acknowledgment message if the downlink site is ready to receive data.

DG2) A DG may only be received during a valid "Transmit Data" transaction.

Connection Attempt Failed

UB1) The SCS shall receive a UB (uplink bad) acknowledgment message if the uplink site is not ready to receive data.

UB2) The SCS shall terminate a customer data communications time slot for rescheduling if it receives a UB from the uplink site. Upon receipt of a UB, the SCS shall prepare and send a TSCAN (time slot canceled) command message with a status code of "0" to the GCS.

UB3) A UB acknowledgment may be received only during a valid "Transmit Data" transaction.

DB1) The SCS shall receive a DB (downlink bad) acknowledgment message if the downlink site is not ready to receive data.

DB2) The SCS shall terminate a customer data communications time slot for rescheduling if it receives a DB from the downlink site. Upon receipt of a DB, the SCS shall prepare and send a TSCAN (time slot canceled) command message with a status code of "1" to the GCS.

DB3) A DB acknowledgment message may be received only during a valid "Transmit Data" transaction.

The corresponding Requirement Behavior Tree is as below: (click the image to see the full size graph)