Wi-Fi Location


位置與移動性密不可分。無論在室內還是室外,消費者都想知道他們在哪裡,周圍有哪些東西。Wi-Fi CERTIFIED Location™在室內提供達到米級的準確度。憑藉Wi-Fi連接的優勢,無需單獨的定位基礎設施或費用高昂的維護,支援Wi-Fi Location的網路和設備就可聯手提供準確的定位資訊。

支援Wi-Fi Location的設備説明網路系統管理員、作業系統開發人員和應用開發人員提供先進的、以定位資料為主導的應用和服務。Wi-Fi Location認證確保基於標準的設備互通性,以便開發人員能夠為用戶提供與室外相同的室內體驗。


Wi-Fi Location允許自我定位的接入點建立準確的室內位置,並使6GHz標準功率的應用可用。通過使用FTM範圍請求和報告,客戶設備可以在不分享任何資訊的情況下確定其相對於傳播接入點的位置,從而在不損害隱私的情況下提供極大的準確性。Wi-Fi Location不僅提高了導航定位數據的準確度,還為開發新的、功能豐富的應用和服務創造了條件。Wi-Fi 無處不在,無需額外設備即可輕鬆利用現有網路基礎設施來實現準確的室內定位。Wi-Fi Location可以通過以下應用和服務,造福工業、企業、零售和醫療保健市場:

  • 室內導航:Wi-Fi Location精確到一米以內,並提供每秒數次的更新;
  • 資產管理:跟蹤高價值移動設備;
  • 網路管理:準確定位哪里需要排故和維護;
  • 地理圍欄:建立虛擬邊界,當設備進出邊界時,觸發行動;
  • 自我定位的接入點:Wi-Fi Location允許自我定位的接入點建立準確的室內位置,並使6GHZ標準功率的應用可用。
  • 緊急服務:Wi-Fi Location能夠運用公民地址及樓層號碼進行定位,有可能幫助縮減應急服務回應時間。

Frequently Asked Questions

Does Wi-Fi Location coexist better with a Wi-Fi data service and ensure quality of service compared to other localization technologies?

A localization service is part of a larger connectivity service. By using the Wi-Fi network to provide location services, native co-existence is achieved between the location and core data connectivity service. This kind of native support results in an ability to maintain the QoS of the data service, while ensuring the performance and accuracy of the location service.

How do environmental factors affect Location accuracy?

The environment can play a role, and introduce multipath, which may cause the range to be overestimated. This includes building materials, the presence of RF reflectors such as HVAC metal ducting, and some eco-glass designed to reflect the sun’s rays, but also reflects RF. Often these effects are transitory for a mobile device, and a typical motion filter will remove them from the estimated path.

How does the Wi-Fi channel bandwidth affect location precision?

Location precision is inversely proportional to bandwidth. If an 80 MHz channel bandwidth results in a location precision of 1 meter, then for a 160 MHz bandwidth channel, the precision will be roughly 0.5 meters.

At what rate can Wi-Fi Locations be estimated to support indoor navigation?

This depends on the implementation, but there are commercial examples of devices that can range to 6 access points at 2-3 Hz. When combined with digital maps, this results in a smooth turn-by-turn navigation experience. The ranging rate when multiple devices are positioning at the same time will also affect network utilization and needs to be considered when a network deployment is being planned.

What are the network infrastructure benefits of accurate Wi-Fi Location?

For the Wi-Fi infrastructure venue owner, Wi-Fi Location provides a valuable additional user-facing location service (see "What are the primary uses of Wi-Fi Location?” for examples), with no additional operational cost, and may even save running costs by helping the owner maintain their network, locating access points after site remodels.

What are the mobile client benefits of accurate Wi-Fi Location?

Wi-Fi Location enables a mobile client to determine its location to an accuracy of about 1 meter (at 80 MHz bandwidth), when operating within a Wi-Fi network. There is no additional hardware cost, or any significant impact on battery lifetime.

What is the value of Wi-Fi CERTIFIED Location?

Wi-Fi CERTIFIED Location ensures a Wi-Fi product conforms to the IEEE standard with respect to the FTM protocol and can operate within the accuracy expected for range estimation. Positioning and applications, such as indoor navigation, can be supported when all participating devices have certification.          

What is the difference between ranging and location?

Wi-Fi ranging estimates the distance between two devices using the FTM protocol. When three or more ranges to nearby access points at known positions are combined, the mobile device can estimate its own location (or position) on a map.

What are the primary uses of Wi-Fi Location?

Wi-Fi Location can be used where GPS cannot. A typical location-based application is positioning and route finding inside a building (aka indoor navigation), allowing users to be directed to a specific place, thing, or product. It also enables proximity applications, which include wireless keys/locks, smart home control (actions triggered by relative positions of devices), and access-control to digital resources based on location.

What is the difference between Wi-Fi Aware and Wi-Fi Location?

Wi-Fi CERTIFIED Location™ is used for determining device location within a network by finding and connecting to access points, whereas Wi-Fi Aware is about connecting directly to other devices to publish and advertise information and services without an access point. Wi-Fi Location™ and Wi-Fi Aware can be utilized for similar uses, such as geo-fencing or personalized shopping, but Wi-Fi Location is meant to operate within Wi-Fi infrastructure to deliver precise location determination. Wi-Fi Aware is focused on connecting devices within an area of proximity without a network infrastructure.

How does Wi-Fi Location determine a mobile client device’s location?

Wi-Fi Location uses the time-of-flight (ToF) of IEEE 802.11 frames to locate a device within a network (also called round-trip-time (RTT)). It is based on the Fine Timing Measurement (FTM) protocol, enabling a mobile device to estimate its distance relative to one or more fixed position Wi‑Fi access points (APs) in the network. The mobile device can then combine these measurements, and locate itself on a floorplan, map or in latitude and longitude coordinates.

Does my client device need to be associated with an access point on a network to determine location?

No, using Wi-Fi Location, a client device can negotiate with an access point (AP) to determine its location even when the client device is not associated with that AP.

Must both client and network devices be Wi-Fi Location enabled for Wi-Fi Location to work?

Yes, both client and network infrastructure devices must be Wi-Fi Location enabled to support positioning.

How many infrastructure devices are needed to accurately determine a device’s location?

To determine its location on a map, a mobile client device must use a minimum of three distance measurements to nearby access points at known positions, a process called trilateration. However, more distance measurements to additional access points improves location accuracy, and typically avoids inaccuracies introduced by poor access point layout.

Is Wi-Fi Location power efficient?

Yes. Wi-Fi Location minimizes its impact on client battery life by allowing a device to negotiate the scheduling, and operational parameters, for a Fine Timing Measurement (FTM) protocol exchange. A single RF distance measurement can be completed in as little as 0.5 milliseconds.

Wi-Fi Alliance Member Publications