The BattleNet is a communications network (similar to and prossibly based on the ansible from the Ender's Game series). Honestly the closest thing SotP has to a comm network is pinging and chat, neither of which can really be changed (as far as I know?). I was thinking that this could have more to do with planet/ship vision. Or to go another route, some kind of team bonus for the Covenant to make it easier to coordinate strikes, and to counter that a team bonus for the UNSC to be able to anticipate strikes (because Cortana knows what they're plotting).
On the UNSC end of this I have two ideas for orbital stations that can counter a BattleNet. I think the UNSC already has all the defense it needs from an Anchor/SMAC/Sabre combo. These stations would fill a more auxiliary role.
1. Remote Scanning Outpost
A listening post is mentioned in both The Fall of Reach and Halo 2. They can detect Covenant fleets and allow the UNSC to do some last minute prepping for an assault.
http://halo.wikia.co...canning_Outpost
2. Gamma Station
Gamma is mentioned in The Fall of Reach and is a DLC map for Halo: Reach. This station is able to refit and repair ships. Perhaps this could be the new look for the UNSC's refit and repair station. It could also potentially be a "second starbase" since that idea seems popular around here. I don't necessarily think it should be a star base though because the UNSC's defense is already pretty good.
http://halo.wikia.co...h_Station_Gamma
Food for Thought.