Siemens CP 1515 - Manual (Page 125)

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Industrial Ethernet Wireless LAN RLM Manager, CP 1515 Manager
C79000-G8976-C171-01
125
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If you decide to split the LAN (segment) into multiple (sub)
segments, make sure that all SIMATIC NET Industrial Wireless LAN
equipped devices will be grouped into the same LAN segment.
Wireless stations will not be able to roam between LAN segments
that are separated by routers and/or gateways.
If this does not solve your problem, consider one of the following options as
described in this chapter:
• Protocol Filtering (page 118)
• Optimizing Wireless Connections (page 125)
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When the link quality of communications between a wireless station and its
Access Point RLM is poor, packets communicated between this station and
the Radio Link Module may get lost. Waiting in vain for an acknowledgment
of the receiving station, the sending station will re-transmit the lost packet.
Upon receipt of the same packet for the second time, the receiving station
might decide to discard all packets received so-far, which would require that
the sending station will have to retransmit all packets once again.
Please note that:
• Many retransmissions may affect your effective data throughput
efficiency as the “true data” has to share the wireless bandwidth with
the re-transmitted frames.