3Com PLM Series, NCG-PLM manual Improving Wireless Accessibility, Wireless Network Topologies

5 Network Connections and Topologies

devices (or sinks) for a given latency setting. Table

5.4shows the limits for a Dante system with PLM Series devices as the sinks.

The recommended system is shown in grey in Table

5.4.It has a DLP or PLM as the source (100 Mbps) and PLM Series devices as sinks. The first and last hops are 100 Mbps; all other hops, including those between switches, are 1000 Mbps.

If the latency is assumed to be 1.3 ms we can have 34 hops from the source devices to any PLM. If we assume 3 x PLMs per rack in any variant of the daisy chained switch topologies (ring or dual chain), we could then support a system with 33 racks, giving 99 PLMs (396 channels).

If the topology is layered or star/spoke, the system could be even larger. The DLC PLM Edition software user interface is designed to display 125 PLM Series devices on an XGA screen.

A system of this size has been assembled and verified by Lab.gruppen engineering at our factory location.

for use in larger venues; however local legal restrictions may apply in some countries. Please contact your Lab.

gruppen distributor for advice if necessary.

5.6Improving Wireless Accessibility

Primary and Secondary PC

In applications where maintaining control and monitor- ing throughout the event is critical, and yet where mobile control access is also desired, users should have a primary control PC connected via wire in conjunction with a wireless secondary PC.

Multiple access points, single SSID

Two or more access points can be connected to the same network as long as they are given the same SSID, the name used to identify a particular LAN within range of a PC. (See section 7 References and Defini- tions for more information.) The user can then move freely around the venue and maintain connection to the network via the closest access point.

5.5 Wireless Network Topologies

Adding wireless networking to the system provides portable, centralized control to a distributed network of PLM Series devices (as well as other Dolby Lake processors.) A wireless network greatly enhances the flexibility of control of a large audio system, as the control location is not fixed. A wireless access point simply works as a gateway between the wired network and wireless devices. A Tablet PC running the Dolby Lake Controller PLM Edition software then communicates with the access point wirelessly, al- lowing control of the system from anywhere in the venue that is within wireless range

Wireless connections are generally slower than wired connections, and can result in varying degrees of Ethernet performance. Connection quality can depend on the

distance and angle to the access point as well as the presence of any surrounding interference. Strong interference may lead to loss of connection.

5.7Using Dante in Conjunction with Wireless Networks and Low Bandwidth Devices

For Dante to operate on a network link, the network has to provide a bandwidth of at least 100 Mbit/s. Hence Dante does not operate over wireless links. In order to attach a wireless accesspoint to a Dante enabled network, special attention needs to be taken to make sure the Dante packets do not flood the wire- less link. A switch that is configured to filter out the Dante packets must be installed at the boundary of the wireless network.

Dolby Lake legacy products such as Contour and Mesa Processors are 10 MBit/s devices. If these devices are to be connected to a Dante enabled network, the same type of filtering of Dante packets is necessary. Please refer to the Audinate document “AUD-ANO- ACL_Filtering_SRW224G4-V2.4.pdf” for further details regarding filtering of Dante packets.

Booster antennae are highly recommended

12PLM Series Network Configuration Guide