Airport WDS Network and the 5GHz Option

Question

Setting up any Airport base station with basic settings is simple but there always seem to be options that are not well covered in the 'manual' when setting up slightly more complex networks. I'm hoping someone can provide some clarification on our configuration or parhaps some advice.
For many years we have used a series of generations of Aiport basestations to create a WDS (wireless distributed) network. This is where one base station is the master and other base stations extend the range of the network wirelessly. This is not a set of wireless basestations creating an extended network by sitting on an ethernet backbone - that's a different configuration.
Anyway, we now have a Time Capsule, an Airport Extreme, and an Airport Express. The Time Capsule is the master and the other two base stations extend the network. By default, the basestations select the channel automatically but we have selected manual channels because we have neightbours that all seem to want to sit on channel 1. We've opted for channel 13, a less used channel.
[Internet ADSL Modem]
|
[Airport Extreme] ---- [Time Capsule] ---- [Airport Express]
The Extreme and the Express both operate in Bridge Mode only, that is, they simply extend the configuration of the master basestation and do not ditribute private addresses or do any NAT. I reckon this keeps it simple. Any changes made on the Time Capsule - such as Access Control changes - are pushed out to the other two stations automatically. This seems to be a significant improvement over version 5 of the airport software.
My main question relates to the 5GHz network option. I can turn on a 5GHz discrete network on the Time Capsule. It receives a unique name so it's clearly distinguished from the 2.4GHz network when connecting to it on our Macs. You would expect the other two base stations to be able to extend the 5GHz network too but their 5GHz options remain turned off by default. I can turn them on manually but I'm not sure if they should all be configured to work on the same channel or even if turning them on at all is a good idea.
Over the years, the setup of a WDS network has become easier (if only for the reason that Apple has removed some of the more confusing options and simply enables them in background). But the 5GHz network configuration is far from clear. Any advice anyone might have would be much appreciated. Thanks.

Answer 1

My main question relates to the 5GHz network option. I can turn on a 5GHz discrete network on the Time Capsule. It receives a unique name so it's clearly distinguished from the 2.4GHz network when connecting to it on our Macs. You would expect the other two base stations to be able to extend the 5GHz network too but their 5GHz options remain turned off by default.
It appears as if your Time Capsule is a simultaneous dual band version which produces both a a 2.4 GHz and 5 GHz network.....and you have enabled the option to assign a separate name to the 5 GHz network.
If both your AirPort Extreme and AirPort Express are also simultaneous dual band versions, they can extend both the 2.4 GHz and 5 Ghz signals from the Time Capsule.......but only if the Time Capsule is configured to use the same wireless network name for both bands.
The simultaneous dual band version of the AirPort Express is easy to identify......it looks like a miniature AirPort Extreme.  Check the Model No on the bottom of the AirPort Extreme and report back with that to find out if your AirPort is simultaneous dual band. 
Earlier versions of the AirPort Extreme could produce a 5 GHz or 2.4 GHz network, but not both at the same time.
Once we have clarification on your AirPort Extreme and AirPort Express, we can decide on the options that will be available to you as far as "extending" both bands.