Murata Electronics North America 5811M Manual Do Utilizador
© 2003 Cirronet
Incorporated
5
M-5811-0008 Rev -
Note that if a remote leaves the coverage area and then re-enters, it may be assigned a
different handle.
To detect if a remote has gone offline or out of range, the registration must be “renewed”
once every 256 hops. Registration is completely automatic and requires no user application
intervention. When the remote is registered, it will receive several network parameters from
the base. This allows the base to automatically update these network parameters in the
remotes over the air. Once a parameter has been changed in the base, it is automatically
changed in the remotes. The parameters automatically changed are hop duration and hop set.
At the beginning of each hop, the base station transmits a synchronizing signal. After the
synchronizing signal has been sent, the base will transmit any data in its buffer. The amount
of data that the base station can transmit per hop is determined by the base slot size
parameter. If there is no data to be sent, the base station will not transmit data until the next
frequency.
The operation for remotes is similar to the base station without the synchronizing signal. The
amount of data a remote can send on one hop is dependent upon the hop duration, the base
slot size and the number of remotes currently transmitting data. A detailed explanation of this
relationship is provided in Section 2.2.3.
different handle.
To detect if a remote has gone offline or out of range, the registration must be “renewed”
once every 256 hops. Registration is completely automatic and requires no user application
intervention. When the remote is registered, it will receive several network parameters from
the base. This allows the base to automatically update these network parameters in the
remotes over the air. Once a parameter has been changed in the base, it is automatically
changed in the remotes. The parameters automatically changed are hop duration and hop set.
At the beginning of each hop, the base station transmits a synchronizing signal. After the
synchronizing signal has been sent, the base will transmit any data in its buffer. The amount
of data that the base station can transmit per hop is determined by the base slot size
parameter. If there is no data to be sent, the base station will not transmit data until the next
frequency.
The operation for remotes is similar to the base station without the synchronizing signal. The
amount of data a remote can send on one hop is dependent upon the hop duration, the base
slot size and the number of remotes currently transmitting data. A detailed explanation of this
relationship is provided in Section 2.2.3.
Except for the registration process that occurs only when a remote logs onto the network, the
whole procedure is repeated on every frequency hop. Refer to the section on Modem
Commands for complete details on parameters affecting the transmission of data.
whole procedure is repeated on every frequency hop. Refer to the section on Modem
Commands for complete details on parameters affecting the transmission of data.
2.2. Data Transmission
The WIT5811 supports two network configurations: point-to-point and point-to-multipoint.
In a point-to-point network, one radio is set up as the base station and the other radio is set up
as a remote. In a point-to-multipoint network, a star topology is used with the radio set up as
a base station acting as the central communications point and all other radios in the network
set up as remotes. In this configuration, all communications take place between the base
station and any one of the remotes. Remotes cannot communicate directly with each other.
In a point-to-point network, one radio is set up as the base station and the other radio is set up
as a remote. In a point-to-multipoint network, a star topology is used with the radio set up as
a base station acting as the central communications point and all other radios in the network
set up as remotes. In this configuration, all communications take place between the base
station and any one of the remotes. Remotes cannot communicate directly with each other.
2.2.1. Point-to-Point
In point-to-point mode, the base station will transmit whatever data is in its buffer limited to
65,536 bytes or as limited by the base slot size. If the base station has more data than can be
sent on one hop, the remaining data will be sent on subsequent hops. In addition to the data,
the base station adds some information to the transmission over the RF link. It adds the
address of the remote to which it is transmitting, even though in a point-to-point mode there
is only one remote. It also adds a sequence number to identify the transmission to the
remote. This is needed in the case of acknowledging successful transmissions and
retransmitting unsuccessful transmissions. Also added is a 24-bit CRC to allow the base to
check the received transmission for errors. When the remote receives the transmission, it
In point-to-point mode, the base station will transmit whatever data is in its buffer limited to
65,536 bytes or as limited by the base slot size. If the base station has more data than can be
sent on one hop, the remaining data will be sent on subsequent hops. In addition to the data,
the base station adds some information to the transmission over the RF link. It adds the
address of the remote to which it is transmitting, even though in a point-to-point mode there
is only one remote. It also adds a sequence number to identify the transmission to the
remote. This is needed in the case of acknowledging successful transmissions and
retransmitting unsuccessful transmissions. Also added is a 24-bit CRC to allow the base to
check the received transmission for errors. When the remote receives the transmission, it