SteamVR Base Station 2.0

SteamVR Base Station 2.0
Basic Info
VR/AR	Virtual Reality
Type	Tracking base station
Subtype	Lighthouse tracking emitter
Platform	SteamVR
Creator	Valve Corporation
Developer	Valve
Manufacturer	Valve, HTC
Announcement Date	June 2017 (developer reveal)
Release Date	June 28, 2019 (with Valve Index)
Price	$149 (single unit)
Website	https://www.valvesoftware.com/en/index/base-stations
Versions	SteamVR Base Station 2.0 (also sold as Valve Index Base Station and VIVE Base Station 2.0)
Requires	Compatible SteamVR 2.0 headset/controllers, 12V power outlet
Predecessor	SteamVR Base Station 1.0
Successor	None announced
System
Operating System	N/A
Chipset	N/A
CPU	N/A
GPU	N/A
Storage
Storage	N/A
Memory	N/A
SD Card Slot	No
Display
Display	N/A
Resolution	N/A
Refresh Rate	N/A
Image
Field of View	150-160 degrees horizontal, 110-115 degrees vertical (see Specifications)
Horizontal FoV	150-160 degrees (per source)
Vertical FoV	110-115 degrees (per source)
Optics
Optics	N/A
Ocularity	N/A
IPD Range	N/A
Adjustable Diopter	N/A
Passthrough	N/A
Tracking
Tracking	SteamVR Tracking 2.0 (outside-in laser sweep)
Base Stations	Self (up to 4 per system; up to 16 linkable)
Eye Tracking	N/A
Face Tracking	N/A
Hand Tracking	N/A
Body Tracking	N/A
Rotational Tracking	N/A
Positional Tracking	N/A
Audio
Audio	N/A
Microphone	N/A
Camera	N/A
Connectivity
Connectivity	Wireless sync (sync-on-beam); no inter-station line of sight required
Ports	DC power, micro-USB (firmware/service)
WiFi	N/A
Bluetooth	N/A
Power	12V DC adapter
Battery Capacity	N/A (mains powered)
Battery Life	N/A
Charge Time	N/A
Device
Dimensions	80 x 74 x 63 mm
Weight	Approx. 266 g (base station unit)
Material	Plastic housing
Headstrap	N/A
Haptics	N/A
Color	Black
Sensors	Spinning IR laser rotor + IR LED flood array
Input	N/A
Compliance	SteamVR Tracking 2.0

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The SteamVR Base Station 2.0 is a virtual reality tracking device developed by Valve Corporation as part of the second generation of its SteamVR Tracking system. The unit is a stationary emitter, sometimes called a "Lighthouse", that floods a room with infrared light and sweeps it with a rotating laser plane so that photosensors on headsets and controllers can calculate their own position and orientation with sub-millimeter precision. It is the tracking foundation for the Valve Index and is also sold under the HTC brand as the SteamVR Base Station 2.0 (and as the VIVE Base Station 2.0) for use with the HTC Vive Pro. First shown to hardware licensees in 2017 and released to consumers on June 28, 2019 alongside the Valve Index, the 2.0 base station replaced the original SteamVR Base Station 1.0 with a single-rotor design, a wider tracking field, a wireless synchronization scheme, and support for up to four units covering a play space of roughly 10 by 10 meters.

Background

SteamVR Tracking, originally branded "Lighthouse", debuted with the HTC Vive in 2016. In that first-generation system, each base station contained two spinning rotors that swept horizontal and vertical infrared laser planes across the room, preceded by a synchronization flash from an array of infrared LEDs. A device's photodiodes timed the interval between the sync flash and each laser sweep to triangulate position. The original setup was limited to two base stations, which had to maintain line of sight with each other (or be joined by a wired sync cable) and together covered a play area of roughly 4 by 4 meters.

Valve publicly detailed the second-generation system in June 2017, presenting it to SteamVR Tracking licensees as a cheaper, smaller, lighter and more reliable design that would eventually support more than two base stations and enable larger, even multi-room, tracking volumes. The first commercial product to use 2.0 tracking was the HTC Vive Pro, shown at CES in January 2018, but the base station was sold as a standalone accessory when the Valve Index launched in 2019.

Design and technology

The defining change in the 2.0 base station is its single-rotor architecture. Where the 1.0 unit used two motors and a separate omnidirectional sync blinker, the 2.0 unit uses one spinning rotor whose laser sweeps the room about 100 times per second. The synchronization signal is encoded into the laser beam itself, a method Valve calls "sync-on-beam", so the units no longer need the LED sync flash that previously caused interference between stations and added cost. Because each station carries a unique identifier in its coded sweep, the base stations no longer need to see one another, removing the line-of-sight and sync-cable requirements of the first generation and making multi-station layouts much easier to set up.

Valve states that the fixed lasers sweep 100 times a second to track the photonic sensors on the headset and controllers, yielding sub-millimeter accuracy. Valve also notes improved immunity from interference by depth cameras and motion-capture systems compared with the previous generation. The single-rotor design is quieter and lower power than the dual-rotor 1.0 unit.

Sensor compatibility

SteamVR Tracking devices detect the laser sweep using a photodiode receiver chip made by Triad Semiconductor. The first generation used the TS3633 sensor; the 2.0 base stations require the newer TS4231, which Triad developed to be cheaper to manufacture (the assembly was reduced to roughly five components) and compatible with both old and new base stations. The practical consequence is an asymmetry in cross-generation compatibility:

• Devices built with the older TS3633 sensor, including the original HTC Vive headset and its wand controllers, do not work with 2.0 base stations.
• Devices built with the newer TS4231 sensor, such as the Valve Index and HTC Vive Pro, remain compatible with 1.0 base stations as well as 2.0 base stations.

A single tracked system must use base stations of the same generation; 1.0 and 2.0 units cannot be mixed within one setup.

Coverage and play space

A 2.0 system supports up to four base stations, double the two-station maximum of the first generation. Two units cover a typical room-scale area, while a third can be added to fill awkward corners and a fourth to reach the maximum supported play space of about 10 by 10 meters (roughly 33 by 33 feet), an area Valve describes as around four times larger than a two-station 1.0 setup. Each station has an effective range on the order of 7 meters from the tracked devices.

The system can scale beyond a single room. In August 2018, HTC demonstrated up to 16 SteamVR Tracking 2.0 base stations linked together (using a SteamVR beta that added radio-based channel configuration) to form a single continuous tracked volume spanning multiple rooms, in one test covering about 67.5 square meters.

Synchronization and setup

Earlier base stations were configured with letter channels (b, c) and could require a sync cable, but 2.0 base stations are assigned to numbered channels and synchronize wirelessly through their coded laser sweeps, so they do not need to face or "see" each other. Each unit is typically wall-mounted above head height, angled downward toward the play area, and powered from a 12V DC adapter; Valve notes the 2.0 unit is compatible with existing HTC Vive power supplies.

Specifications

Specification	Detail
Type	Outside-in laser tracking base station (Lighthouse / SteamVR Tracking 2.0)
Rotor design	Single rotor (sweeps approx. 100 times per second)
Synchronization	Sync-on-beam (encoded in laser); no inter-station line of sight or sync cable
Tracking precision	Sub-millimeter
Field of view	160 degrees horizontal / 115 degrees vertical (Valve marketing); 150 degrees horizontal / 110 degrees vertical (HTC/VIVE support documentation)
Range	Approx. 7 meters
Base stations per system	Up to 4 (up to 16 linkable via SteamVR beta)
Maximum play space	Approx. 10 x 10 m (about 33 x 33 ft) with 4 units
Required sensor	Triad Semiconductor TS4231 photodiode receiver
Power	12V DC adapter (compatible with HTC Vive power supply)
Compatible headsets	Valve Index, HTC Vive Pro (and other SteamVR 2.0 / TS4231 devices)
Incompatible	Original HTC Vive headset and wand controllers (TS3633 sensor)
Predecessor	SteamVR Base Station 1.0
Release date	June 28, 2019 (with Valve Index)
Price	$149 (single unit, USD)

Sources differ on the exact field of view: Valve's product marketing lists 160 degrees horizontal and 115 degrees vertical, while HTC/VIVE support documentation lists 150 degrees horizontal and 110 degrees vertical for the same hardware. Both figures appear in official channels.

Availability and pricing

The SteamVR Base Station 2.0 began shipping on June 28, 2019, the launch date of the Valve Index. Valve sold a single base station for $149. The full Index "Valve Index VR Kit" bundle, priced at $999, included the Index headset, the Valve Index Controllers (Knuckles), two 2.0 base stations, and the required cables and mounts. Existing HTC Vive owners who already had compatible 1.0 base stations could instead buy a $749 headset-and-controller bundle and reuse their older tracking hardware. The unit was also offered through HTC and VIVE storefronts as the SteamVR Base Station 2.0 for use with the HTC Vive Pro.

See also

• SteamVR
• Valve Index
• Valve Index Controllers
• Lighthouse
• Lighthouse Motion Tracking
• HTC Vive Pro