WiFi: Load balancing through probe response control

Basic Idea:

Clients use probe requests as one of the first frames before connecting to an access point (AP). If the AP does not respond with a probe-response frame, the client will not proceed with the connection. We leverage this condition to control how clients are distributed across multiple access points in the network. This approach to client - balancing has the advantage that:

1. Load both RF and CPU are balanced across the APs.

2. No disconnect/connect is required for load balancing.

3. Leverages the fact that typical WLAN mobility is pseudo-static. So clients will not move significantly from the places where they connect. Even in case of mobility, the disruption is minimal.

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Dynamic Load Balancing for WiFi

With WLANs and WiFi architecture moving more towards software than a "burnt in the silicon" approach, it is possible to have different software components running at different points in the network. 

Consider for example the following functions that need to be done in the typical transmit lifecycle of a packet received on the ethernet interface that is supposed to go out on a WiFi interface:

1. Ethernet receive handling
2. Basic ethernet classification and fowarding
3. Stripping of headers
4. Attaching LLC headers
5. Attaching WiFi headers
6. Queening frames for transmission
7. DMA'ing frames
8. Scheduling frames for transmission
9. Aggregation at different layers
10. Encryption

Wireless Channel Power Control

Our ideas for a hybrid approach for channel power control have been discussed here:

S. Ganu, G. Bhanage, P. Narasimhan, "System and Method for Computing Coverage Set and Resource Allocations in Wireless Networks", US Patent App. 13/563,500, 2014.

The key difference as noted in the application is that in some cases we propose using a combination of centralized and de-centralized channel power control i.e. the main channel allocation is done centrally and the local channel flips (based on radar etc) are done locally by the access point.

We propose doing a 2 phase channel allocation strategy:
1. Anchor channels: The baseline RF characteristics of a deployment rarely change i.e. the relative position of the infrastructure APs does not change, the other architecture of the building and basic coarse grained pathloss do not change over large time frames. We use this knowledge to come up with a coarse grained anchor channel assignment for each access point. This anchor channel will be a home channel based on the available

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Uplink Airtime Fairness Control

Problem statement:
There is currently no direct way to control uplink airtime usage of wireless clients on a WLAN without actually implementing something on the client. This is not always possible because of multiple reasons:
Diversity in the operating systems and hardware of client devices.
Privacy issues
General aversion to install 3rd party control software.

Abstract of the idea:
In this case, we address the issue of limiting the airtime used the clients in the uplink direction by controlling the TCP window size in the uplink direction. We do this by doing a deep packet inspection of open TCP sessions for every client and then appropriately limiting the advertised TCP window based on bandwidth consumption by the clients.
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Hybrid Wireless Virtualization Architecture

This project presents the design of the hybrid wireless virtualization (HWV) controller based network architecture. Using a HWV controller, an unified approach can be taken for provisioning and management of virtualized heterogeneous radios, irrespective of their MAC and PHY mechanisms. It is shown that the airtime occupancy by transmissions from different slices or groups can be used as a single metric for tying these virtualized platforms.