802.11n channel bonding and 802.11ac backwards compatibility
Posted on 2014-10-12
I'm about to set a design with Cisco 1702 or 2702 APs (Cisco WLCs are already in place). The environment is a school. The majority of devices are smartphones then laptops and last tablets. 802.11n at 5 GHz and channel bonding is supported since Ihone 5 (sep 2012) and erlier in some cases with Android phones which makes me mainly focused at 5 GHz. Channel bonding seems like a "must-have" when the environment consists of many 1 spatial stream devices. 802.11n at 2,4 GHz will be more of best effort (since there are another 2,4 GHz network in the same building and avoiding interference will be tough).
My questions to you are:
1. What effect will channel bonding have when there are older clients online that doesn't support channel bonding? Will the AP be able to talk with a 20 MHz range to old clients and 40 MHz to newer clients or will they all be degraded to 20 MHz?
2. 1702 and 2702 APs can use 802.11ac. Can they be configured to use 802.11ac with 40 MHz bandwidth and still support 802.11n clients (both with and without channel bonding support).
3. In Europe we only have 4 non-DFS channels and they are all used by an adjacent network which leaves me with DFS channels only. I know Iphone 5 support all DFS channels, but can you give me some examples of devices that don't?
4. How near can a small airport be before I should get worried about DFS channel interference?
5. How would Cisco ClearAir help me with adjacent networks?
6. I've heard that 802.11ac networks won't be degraded to the speed of the slowest client, that it can send at different speeds to multiple clients. How does it work technically? What technologies are used? Anything Cisco proprietary? Have in mind that majority of the clients are smartphones with only 1 spatial stream (if that would make things different).
7. According to Cisco, 20 Mbps throughput could be expected with a PHY data rate of 75 Mbps in high density client environments. Would that 20 Mbps be regardless of encryption standard? The obvious choice feels like WPA2/AES.
I would deeply appreciate your answers - single question answers too.