Q: Would an 802.11b/g network be adequate for limited multimedia (a few IP cameras, a few users), or do I need to move to 802.11a?
- Milan C.
The Wizards gaze into their crystal ball and respond:
Bob O'Hara, Airespace
Generally speaking, an 802.11b network would be sufficient to operate a few IP cameras. With an 802.11g network you could increase the number of devices deployed by as many as 3-to-5 times more due to the increased bandwidth.
To get at the heart of your question, namely how much bandwidth is required to run a specific application, we need to take a look at a number of important factors.
First, how much bandwidth does any application require in order for it to operate as desired? In the case of IP cameras, configuration settings such as frames per second, camera resolution, and the type of compression (if any) used, greatly affect how much bandwidth is required to achieve adequate performance levels.
Once you know how much bandwidth a single device requires, multiply that number by the total number of devices running the same application on the WLAN to come up with your overall bandwidth requirements.
The final variable - determine what kind (if any) of bandwidth discipline or QoS will be employed on your WLAN. For WLANs running real-time applications without QoS, the total amount of available bandwidth decreases. This is because real-time applications without QoS will fight over available bandwidth, causing an overall degradation of bandwidth due to packet collisions.
QoS will eventually be built into all WLAN devices, enabling real-time applications to operate more efficiently as far as bandwidth usage is concerned. For enterprise deployments, intelligent WLAN systems exist today that provide robust QoS capabilities for dynamic bandwidth provisioning and efficient management of real-time applications.
Robert Myers, Chantry Networks
The devil is always in the details, but an 802.11g network should be adequate for the number of devices and users you described. Most IP cameras do not generate significant traffic (hundreds of kbit/s). Most 802.11g access points can deliver more than 20 Mbit/s of real user bandwidth, leaving plenty of bandwidth available for the users.
Scott Haugdahl, WildPackets
Sure, 802.11 b/g would be adequate for limited multimedia - if the users remain few and there’s little or no interference from other devices sharing the unlicensed 2.4 GHz spectrum, such as nearby access points on the same channel (which may be outside your company), Bluetooth, cordless phones, and microwave ovens. On the other hand, even though the unlicensed 802.11a band is a bit more open at the moment, its range is shorter [Check this one out because vendors say new chipsets give as good a range as 802.11g - Editor], and 802.11a is not as competitive in terms of pricing, available equipment and options. If you can get the equipment and support you need and the 802.11a range meets your requirements, by all means give it consideration.
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