BSDCan2013 - Final

BSDCan 2013
The Technical BSD Conference

Adrian Chadd
Day Talks - Day 2 - 2013-05-18
Room MNT 202
Start time 11:30
Duration 01:00
ID 386
Event type Lecture
Track Hacking
Language used for presentation English

The future of wireless networking - mobile, gigabit and beyond

This presentation will cover the current state of wireless technologies in BSD (at least focusing on 802.11 and Bluetooth) and how well (or not) each is implemented and supported by the various BSDs. This includes the classic operating modes (hostap and station modes) as well as newer developments (TDMA, 802.11s, P2P/TLDS, Bluetooth/802.11 PHY sharing.) It will then cover upcoming technologies - 802.11ac, 802.11ad, hybrid operating modes, aggressive mobile power saving technologies - with the technical, architectural and structural changes required to make these technologies a reality.

The BSD operating systems all have varying levels of 802.11 and bluetooth support, however it has split over the years and feature support could be considered "spotty". With support for now mature technologies lacking - such as wireless QoS, 802.11n; client-side power save; AP side power save support, the BSDs have quite a lot of catching up to do. FreeBSD's netgraph based bluetooth stack is elegant and flexible, yet is missing some modern features (bluetooth/802.11 hybrid PHY operation support in Bluetooth 4.0, A2DP support to name just two.)

All of these features are viewed as a prerequisite before BSD will be viewed as a serious contender in modern technology deployments involving wireless technology. Notably, this includes mobile and tablet devices, as well as access points and similar devices.

The first part focuses on what's been done:

  • Which features each of the OSes implement;
  • What we do and don't do well;
  • The developments in FreeBSD and DragonflyBSD in order to stabilise the net80211 stack and drivers;
  • Lessons learnt in making net80211 "SMP correct", with all of the locking/parallelism issues that were exposed;
  • Lessons learnt from 802.11n and 802.11s development.

Then, where things are going:

  • Newer bluetooth (and low-power) support;
  • 802.11ac and 802.11ad support;
  • Where 802.11s is heading;
  • Some of the "stranger" deployments (eg 802.11 variants being trialled between cars, whitespace technology support)

And the final part will focus on what has to happen to the wireless stack to make this a reality:

  • The new 802.11ac channel plan (80, 160 and split 80+80MHz channels);
  • Adding new frequencies (instead of 2/5GHz) - (eg 3GHz, 400MHz UHF ranges for whitespace/TV bands; 60GHz for 802.11ad);
  • The challenges involved in building a network stack that will handle 1+ gigabit/sec throughput (802.11ac / 802.11ad) with the 802.11 state and processing that will be performed;
  • Some of the challenges involved in exposing PCIe devices over 802.11ad, with transparent device hotplug.