Detecting indoor and outdoor usage of a mobile device

Mobile devices may be subject to different operational constraints in different geographies or circumstances. For example, power levels may be limited for transmissions in certain countries. The geographic position of a mobile device may be identified and used for determining the applicable local regulations. The local regulations may allow for different operational constraints depending on whether a device is located indoors or outdoors. Accordingly, a determination of indoor/outdoor state may be used to maximize device performance while also complying with appropriate regulations/circumstances.

BACKGROUND

Mobile devices may be subject to certain regulatory requirements in different countries. For example, there may be regulatory requirements that affect usage options for some radio frequency (RF) system channels, such as wireless fidelity (Wi-Fi) frequency bands, with respect to transmitted power levels and/or frequencies. The regulations may be different depending on whether a mobile device is operating indoors versus operating outdoors.

Current products may be configured with the most restrictive operational limitations implemented, and apply those restrictions in all cases, regardless of location. In this case, the mobile device may be unnecessarily under-performing when the device is operating in a more loosely-regulated environment. Alternatively, a device configured with the most loosely-constraining operational limitations may provide a user option for selecting the more restrictive limitations at the appropriate case. In this case, there is a risk that the user will fail to comply with the regulatory requirements, as a result of either being unaware or uncooperative.

DETAILED DESCRIPTION

The disclosed systems and methods identify a geographic location or position of a mobile device and determine whether the device is located indoors or outdoors in order to comply with governing regulations for that location. Since the regulations in certain countries may change depending on whether the mobile device is indoors or outdoors, that location determination may be used to maximize performance of the mobile device while still complying with applicable regulations. The position of a mobile device may be used for determining the appropriate regulations. For example, different countries may have different regulations regarding transmitted power levels or transmitted frequencies. Those regulations may also be different depending on whether a device is located indoors or outdoors. Accordingly, an identification of geographic position and determination of indoor/outdoor state may be used to maximize device performance while also complying with local regulations.

FIG. 1illustrates an exemplary communication network. An access point (AP)104in a network102that is available for connection broadcasts wireless signals to one or more devices, such as a mobile device106. The mobile device106may also be referred to as a wireless terminal, terminal, device, or electronic device and is further described below with respect toFIG. 2. As shown, the mobile device106is in wireless range of the AP104. The AP104is further described with respect toFIG. 3. Network information or other data may be communicated over the network102. There may be a plurality of access points (e.g. AP104) that provide access to respective access networks (e.g. network102) for a plurality of wireless mobile devices (e.g. mobile device106). Access points (e.g. AP104) may be one or more of Wi-Fi access point, base station, Node B, and enhanced Node B. The provided network may be a Wi-Fi network, a cellular network such as GSM, EDGE, UMTS, LTE, cdmaOne, CDMA2000, WCDMA, a network that provides global positioning system (GPS) signals, or a wireless personal area network whose signals are carried via technologies like IrDA, Bluetooth, Wireless USB, ZigBee, etc. For simplicity, the connected network will be described as a Wi-Fi network, but the location state determination and regulation may be applicable for different types of networks and the operational constraints (regulated settings) may not only apply to Wi-Fi signals from the device, but also be applicable to other network communications or settings with the device. For example, other network includes a core network which provides various services to users or subscribers who are connected by one or more access networks.

The AP104and the mobile device106may include a network adapter or network interface card that facilitates connections to a wireless medium. AP104may provide a direct or indirect connection to the network102, which may be either a private network, or a public network, such as the Internet. The network102may be a local network, such as a wireless local area network (WLAN), or may include other mesh, peer to peer, ad-hoc or Wi-Fi direct networks. The network102may be connected with an external network and may provide access for its mobile devices (e.g. the mobile device106) to the external network. The external network may be a subscription service provider network (SSPN) owned or operated by data subscription service providers, Internet subscription service providers, media (e.g., audio/video) subscription service providers, wireless communications subscription service providers, or any combination thereof. The external network may include the Internet or may be connected to the Internet and may, for example, provide subscription-based Internet access to devices, such as the mobile device106.

The network102may be a WLAN. Some WLAN locations or environments may be known as “hotspots” in reference to a location or environment that is within communication range of WLAN signals. WLAN locations or environments may include coffee shops, retail stores, home locations (e.g. homes and apartments), educational facilities, office environments, airports, public transportation stations and vehicles, hotels, etc. Such WLANs are often implemented as access networks that provide access to publicly accessible networks and may be associated with, or support access to, external networks (or WLAN-supported networks) owned and/or operated by subscription-based service providers. For example, an external network can be owned and/or operated by an Internet-access service provider or a telecommunications carrier/service provider that provides subscription-based service for a fee (e.g., a monthly fee). In some systems, a subscriber/user may subscribe to such a service can use wireless network access and/or Internet-access services based on such a subscription when the subscriber is in communication proximity of the WLAN with an appropriate mobile device. In some instances, different WLANs may provide access to different types of network information. For example, some WLANs may provide access to particular subscription service provider networks, and some WLANs may support roaming agreements to allow connections from mobile devices associated with different SSPs.

As described below with respect toFIGS. 4-7, the mobile device106may communicate with the network102from an outdoor state or an indoor state. The indoor/outdoor state of the mobile device106may be referred to as a location state and be used to determine certain settings or operational conditions for the mobile device106(e.g. power and frequency) to satisfy regulations of the current geographical position of the mobile device106. In other words, the settings and communication between the mobile device106and the network102may be modified depending on whether the mobile device106is indoor or outdoor.

FIG. 2illustrates a mobile device106as shown inFIG. 1. A plurality of mobile devices (e.g. the mobile device106) may connect to a particular network. Such devices may also be referred to as terminals, wireless terminals, stations (STA), mobile stations (MS), user agents (UA) or user equipments (UE), and may also include mobile smart phones (e.g., a BlackBerry® smart phone), tablet (e.g., BlackBerry® Playbook), wireless personal digital assistants (PDA), machine to machine equipment, equipment within a smart grid (SmartGrid), equipment within a mesh network (an ad-hoc or peer network), laptop/notebook/netbook computers with wireless adapters, etc. In one embodiment, the mobile device106may be a MS in Intelligent Transport Systems (ITS), and the indoor/outdoor state may be used for detecting tunnels, garages, maritime vessels, ferries, etc.

The mobile device106includes a processor202that may be used to control the overall operation of the mobile device106. The processor202may be implemented using a controller, a general purpose processor, a digital signal processor, dedicated hardware, or any combination thereof. The processor202may include a central processing unit, a graphics processing unit, a digital signal processor or other type of processing device. The processor202may be a component in any one of a variety of systems. For example, the processor202may be part of a standard personal computer or a workstation. The processor202may be one or more general processors, digital signal processors, application specific integrated circuits, field programmable gate arrays, digital circuits, analog circuits, combinations thereof, or other now known or later developed devices for analyzing and processing data. The processor202may operate in conjunction with a software program, such as code generated manually (i.e., programmed).

The mobile device106also includes a terminal message generator204and a terminal data parser206. The terminal message generator204may generate network information messages or data to be communicated over the network102. The terminal data parser206may be used to obtain network information or data from memory (e.g., random access memory210, etc.). For example, the terminal data parser206may obtain network information120that is cached in the mobile device106after receipt from a network.

In the illustrated embodiment, the terminal message generator204and the terminal data parser206are shown as separate from and connected to the processor202. In alternative embodiments, the terminal message generator204and the terminal data parser206may be implemented in the processor202and/or in a wireless communication subsystem (e.g., a wireless communication subsystem218). The wireless communication subsystem218may support one or more communications for Wi-Fi, GSM, EDGE, UMTS, LTE, cdmaOne, CDMA2000, WCDMA, GPS, IrDA, Bluetooth, Wireless USB, ZigBee, etc. The terminal message generator204and the terminal data parser206may be the interface of the mobile device106for communicating with a network. The terminal message generator204and the terminal data parser206may be implemented using any combination of hardware, firmware, and/or software. For example, one or more integrated circuits, discrete semiconductor components, and/or passive electronic components may be used. The terminal message generator204and the terminal data parser206, or parts thereof, may be implemented using one or more circuits, programmable processors, application specific integrated circuits, programmable logic devices, field programmable logic devices, etc.

The terminal message generator204and the terminal data parser206, or parts thereof, may be implemented using instructions, code, and/or other software and/or firmware, etc. stored on a machine accessible medium and executable by, for example, a processor (e.g., the processor202). The terminal message generator204or the terminal data parser206may be stored on or include a tangible storage medium or memory. For example, the terminal message generator204or the terminal data parser206may be implemented in software stored on a memory that is executable by the processor202. Alternatively, the terminal message generator204and/or the terminal data parser206may be implemented in hardware with software functions. The memory for storing software associated with the terminal message generator204and/or the terminal data parser206may include, but is not limited to, computer readable storage media such as various types of volatile and non-volatile storage media, including random access memory, read-only memory, programmable read-only memory, electrically programmable read-only memory, electrically erasable read-only memory, flash memory, magnetic tape or disk, optical media and the like. In one embodiment, the memory may include the random access memory210for the processor202, or may be an external storage device or database for storing recorded ad or user data. Examples include a hard drive, compact disc (“CD”), digital video disc (“DVD”), memory card, memory stick, floppy disc, universal serial bus (“USB”) memory device, or any other device operative to store ad or user data. The memory is operable to store instructions executable by the processor202.

The mobile device106may include a FLASH memory208, a random access memory210, and/or an expandable memory interface212coupled with the processor202. The FLASH memory208may store computer readable instructions and/or data. In some embodiments, the FLASH memory208and/or the RAM210may store the network information fromFIG. 1and instructions for communicating that network information. The processor202may be coupled with the memory (e.g. the FLASH memory208, or the RAM210) for storing software instructions executable by the processor202. The memory may include, but is not limited to, computer readable storage media such as various types of volatile and non-volatile storage media, including random access memory, read-only memory, programmable read-only memory, electrically programmable read-only memory, electrically erasable read-only memory, flash memory, magnetic tape or disk, optical media and the like. The functions, acts or tasks illustrated in the figures or described herein may be performed by the programmed processor202executing the instructions stored in the memory. The functions, acts or tasks are independent of the particular type of instruction set, storage media, processor or processing strategy and may be performed by software, hardware, integrated circuits, firm-ware, micro-code and the like, operating alone or in combination. Likewise, processing strategies may include multiprocessing, multitasking, parallel processing and the like.

The mobile device106may include a security hardware interface214to receive a SIM card from a wireless service provider. A SIM card may be used authentication of the mobile device106for establishing a connection with a network and may be used for identifying a geographic position based on received information from the network. The mobile device106may be provided with an external data I/O interface216. The external data I/O interface216may be used by a user to transfer information to the mobile device106through a wired medium.

The mobile device106may include wireless communication subsystem218to enable wireless communications with access points (e.g., the access point104ofFIG. 1). Although not shown, the mobile device106may also have a long-range communication subsystem to receive messages from, and send messages to, a cellular wireless network. In the illustrated examples described herein, the wireless communication subsystem218may be configured in accordance with the IEEE® 802.11 standard. In other example implementations, the wireless communication subsystem218may be implemented using a BLUETOOTH® radio, a ZIGBEE® device, a wireless USB device, an ultra-wideband radio, a Near Field Communications (“NFC”) device, or a Radio Frequency Identifier (“RFID”) device. In another embodiment, an MS within an ITS may detect locations in tunnels, garages, maritime vessels, ferries, etc.

The mobile device106may include a user interface for communicating from the device. The user interface may be separate component or it may include a speaker220, a microphone222, a display224, and a user input interface226. The display224may be a liquid crystal display, an organic light emitting diode, a flat panel display, a solid state display, a cathode ray tube, a projector, a printer or other now known or later developed display device for outputting determined information. The user input interface226may include alphanumeric keyboard and/or telephone-type keypad, a multi-direction actuator or roller wheel with dynamic button pressing capability, a touch panel, etc. For example, regulations and settings (e.g. operational constraints) corresponding to those regulations may be communicated with or without each of the user interfaces described herein. Likewise, the user input interface226may provide a user with an option for selecting appropriate settings for the device depending on the location and indoor/outdoor state. The speaker,220, the microphone222, the display224, the user input interface226, and/or any combination thereof may be omitted in alternative embodiments. In one embodiment, the mobile device106is a battery-powered device and includes a battery228and a battery interface230.

FIG. 3illustrates an access point AP104. The access point shown inFIG. 3is AP104fromFIG. 1, but may also be illustrative of other access points that provide networks accessible by mobile devices. AP104includes a processor302to perform operations of the AP104. The processor302may be similar to the processor202described above.

The AP104includes an access point message generator304to generate network information communications for providing data to a terminal, and an access point data parser306for obtaining network information communications and data from the mobile device106and/or an external network. The access point message generator304may be similar to the terminal message generator204ofFIG. 2, and the access point data parser306may be similar to the terminal data parser206ofFIG. 2. The access point message generator304and the access point data parser306may be a communication interface for the network provided by the AP104. As with the terminal message generator204and the terminal data parser206ofFIG. 2, the access point message generator304and the access point data parser306may be implemented in software stored on a memory that is executable by the processor302or may be implemented in hardware with software functions executed by the processor302. Alternatively, the access point message generator304and the access point data parser306may be implemented in a wireless communication subsystem (e.g., a wireless communication subsystem312) using any combination of hardware, firmware, and/or software including instructions stored on a tangible computer readable medium and/or a non-transitory computer readable medium. The wireless communication subsystem312may support one or more communications for Wi-Fi, GSM, EDGE, UMTS, LTE, cdmaOne, CDMA2000, WCDMA, GPS, IrDA, Bluetooth, Wireless USB, ZigBee, etc.

The AP104may also include a FLASH memory308and a RAM310, both of which are coupled to the processor302. The FLASH memory308and/or the random access memory (“RAM”)310may be configured to store network information or data that is communicated over the network102. The RAM310may also be used to generate messages for communication with the mobile device106and/or an external network. The RAM310may also store received messages communicated by the mobile device106and/or an external network.

To communicate with mobile devices (e.g. the mobile device106), the AP104may include a wireless communication subsystem312, which may be similar to the wireless communication subsystem218of the mobile device106illustrated inFIG. 2. To communicate with a network or external network, the AP104may include a network uplink communication interface314.

FIG. 4illustrates an embodiment of the mobile device106. The mobile device106may receive global positioning satellite (GPS) signals402and network signals404. The GPS signals402may be signals from any satellite based navigation system like Gallieo, Glonass or Beidou. The GPS signals402may also include an Assisted GPS (A-GPS) signal. The network signals may include any communications or data from the network102such as cellular or Wi-Fi communications via the AP104. The mobile device106may utilize the received signals for modifying or adjusting its settings or operational constraints to comply with local regulations.

An identifier406may identify the geographic position or location of the mobile device106. In one embodiment, the identifier406utilizes a country code or other identification from the base station that is providing the cellular signal to the device. In one example, a mobile country code (MCC) may be used to identify the geographic location, such as a country. The MCC may be part of the International Mobile Subscriber Identity (IMSI) number for identifying a subscriber. The MCC may also be part of the Public Land Mobile Network (PLMN) identity for identifying a network which the mobile device attempts to register. The MCC may be stored on a memory in the mobile device, or a removable card such as Subscriber Identity Module (SIM), Universal Subscriber Identity Module (USIM) or Universal Integrated Circuit Card (UICC) card which can be inserted into the mobile device. The MCC may be provisioned to a mobile device or a removable card by its PLMN operator which has subscription of service for the mobile device or the removable card using technologies like over-the-air (OTA), device management (DM), etc. The MCC may be provisioned from the network to a mobile device in order to provide regulatory jurisdiction information. The MCC may be provisioned from the network to a mobile device so that the mobile device attempts to register to the network and, if registered, determines which regulatory jurisdiction policy stored on the mobile device should be enforced. Alternatively, the parameter of the country may be set up in a Wi-Fi Access Point (AP) for a WLAN when Wi-Fi AP is shipped to certain countries from manufacturers or when it is stocked in stores of certain countries. Alternatively, the GPS signal402may be used to identify the geographic position of the mobile device. The geographic position to be identified may be a country to account for differing regulations between countries. In other words, the exact geographic position may be unnecessary as long as the country is known. Alternatively, the geographic position may be a state or city to account for differing regulations between states or cities. The regulations at any given geographic position may be referred to as local regulations.

Once a geographic position is identified by the identifier406, the appropriate regulations for that geographic location are obtained or retrieved. There may be a separate component (e.g. an obtainer or a retriever) that utilizes the geographic position to establish the appropriate regulations for the current country/state/city of the device. When a mobile device registers to a mobile operator network then the mobile device may know in which country it has registered based on the MCC value. A look-up table (which may be remotely updated over the air with a push service) may list the applicable regulations, indexed by MCC or using an equivalent look-up capability. In another embodiment, applicable regulation policies are embedded in a memory of a mobile device and proper regulation policy is polled out by a mobile device based on the MCC value indicating in which country the mobile device has currently registered.

The determiner408makes a determination as to a current state of the mobile device106. The determiner408may also be referred to as a detector that detects the current state of the device, which is also referred to as a location state or environment state. In one embodiment, the state may reflect the conditions or environment in which the mobile device106is located. The identified and obtained or polled regulations may differ depending on the environmental state of the mobile device106. For example, the allowed wireless radio frequency (RF) power transmission levels may be different depending on the environmental state for the mobile device106. A mobile device106outdoor may be allowed increased RF power, while a mobile device106indoor may be regulated to have less RF power. In another embodiment, a mobile device106indoor may be allowed increased RF power, while a mobile device106outdoor may be regulated to have less RF power. In addition to environmental state and indoor/outdoor state, the determiner408may determine other conditions of the mobile device106or other conditions around the mobile device106that may result in different regulations for that particular geographic location. As described herein as one example, the condition that is determined or detected is whether the mobile device106is the location state of whether a device is in an indoor state or an outdoor state. The determination of an indoor/outdoor state may be referred to as a location state or a condition state and is further described below with respect toFIGS. 5-7.

The regulator410receives the appropriate regulations (and/or the geographic position) from a network or from a memory of the mobile device, as well as the indoor/outdoor state. The settings or operational constraints of the mobile device106may be modified or adjusted to comply with the appropriate regulations in view of the indoor/outdoor state. For example, the power transmission level may be modified or adjusted depending on the indoor/outdoor state and the particular requirements for that country. In the case of Wi-Fi, there may be power or frequency limits depending on the channel of the signal. An alternative operational constraint may be to limit the frequency bands to the lower four Wi-Fi channels in a Wi-Fi signal. In one embodiment, different countries have different power transmission regulations that are also different depending on whether the device is indoor or outdoor. The regulator410sets the power transmission level of the mobile device106to a maximum allowed value for that country and depending on whether the mobile device106is indoors or outdoors.

In an alternative embodiment, this analysis may also apply to cognitive radio. A cognitive radio may be another example of a mobile device106that may adapt to the environment/circumstances. For example, in an area where different services/systems are sharing the same frequency band (in order to improve frequency utilization). In a cellular system where conventional base station operation may be used outdoor, a mobile device that is moving indoor buildings may look for a femtocell access point. Femtocell may also refer to another technology (frequency band, modulation scheme, power level etc.). If found, it may switch and unload the conventional outdoor system, the reduced RF power of the mobile device in the in-building environment allows the mobile to operate in the same band without interfering with the conventional infrastructure. The detector may determine when a mobile device should be looking for a femtocell.

FIG. 5illustrates location state detection and device regulation. In block502, the geographic position (e.g. country) of a device (e.g. mobile device106) is identified. As discussed, there may be an identifier that identifies geography based on a country code or other identification in a received signal (e.g. network signals404) or based on a GPS signal (e.g. GPS402). The geographic position may be a country or state or other area (e.g. metropolitan) with known regulations for mobile devices. In block504, the regulations for that geographic position are determined. There may be a lookup table that includes the regulations for the current geographic position.

With the geographic position and corresponding regulations determined, the environmental or location state of the device is determined in block506. In one embodiment, the location state is determined based on a GPS analysis in block508. In an alternative embodiment, the location state is determined based on multipath propagation in block510. GPS analysis in block508is discussed below inFIG. 6and multipath propagation in block510is discussed below inFIG. 7.

When the location state cannot be established in block512, the user may be prompted for verification in block514. In other words, when both GPS analysis and multipath propagation fail to provide a location state or at least fail to provide a location state with a certain confidence, then the user may be asked to either provide or confirm the location state. For example, when the location state is determined to be outdoor based on either GPS analysis or multipath propagation, but the determination is uncertain, the user may be prompted to confirm that the device is outdoor.

When the location state is known from block512or verified by the user in block514, the device operational settings may be set based on the identified regulations for the particular location state. As discussed above, there may be determiner that determines the location state and a regulator that sets the device to comply with the regulations. The regulator410may change the device's operational settings to or adjust proper regulatory operational settings on the device in block516. In block518, there may be a timer that rechecks for the location state periodically. The timer may be set to check the location state every ten seconds, every minute, every ten minutes, or some other amount of time. In block518, when the timer is triggered, the location state is again determined in block506.

FIG. 6illustrates location state detection with global positioning satellite (GPS).FIG. 6illustrates the GPS analysis in block508ofFIG. 5. The strength of a GPS signal402may be used to determine whether a mobile device is indoors or outdoors. A strong GPS signal602is indicative of being outdoor608. A weak GPS signal604is indicative of being indoor610. In one embodiment, a GPS signal may usually include signals from three or more satellites which would indicate a strong signal in an outdoor state608. If the signal is from no satellites or a few satellites, it may indicate a weak signal604, and the location state is considered to be indoor610. In another embodiment, when a mobile device operates in Assisted GPS (A-GPS) mode the location state may be considered to be indoor610. In A-GPS, network operator deploys an A-GPS server which downloads orbital information like ephemeris and almanac directly from one or more satellites and stores the orbital information in the database. The mobile device connects to the A-GPS server via an access network (e.g. GSM, EDGE, UMTS, LTE, cdmaOne, CDMA2000, WCDMA, Wi-Fi) and downloads the orbital information via the access network. Accordingly, as described herein, the indoor/outdoor state may be determined by the GPS signal strength or A-GPS mode operation.FIGS. 8-10illustrate alternative embodiments for determining a location state based on a GPS signal, an A-GPS signal, and a communications signal, respectively.

Determining indoor/outdoor state based on GPS signal strength or A-GPS mode operation may be quicker and more efficient than determining whether a device's GPS positional coordinates corresponds to an indoor location, although that is a possible way to determine location state. Even when the GPS coordinates may not be known due to a weak signal or too few satellites, the location state may still be determined based on signal strength.

When the GPS signal is detected from one satellite606, the location state may be uncertain as to whether the device is outdoor or indoor. In one embodiment, a GPS signal from one satellite606may be considered an outdoor state, but with less certainty than a GPS signal with two or more satellites. In other words, a GPS signal from one satellite generally represents a weaker signal, and may be indicative of uncertainty regarding the location state (e.g. block514ofFIG. 5).

FIG. 7illustrates location state detection with multipath propagation.FIG. 7illustrates the multipath propagation in block510ofFIG. 5. Multipath propagation510may be an alternative method to the GPS analysis508for determining location state. In one embodiment, when the GPS analysis508is uncertain regarding the location state, the multipath propagation510may be used. Multipath propagation may analyze the network signals404to determine whether the paths of those signals have bounced off multiple sources. A limited number of multipath signals702may be indicative of a location state that is outdoor706. Numerous multipath signals704may be indicative of a location state that is indoor708.

Multipath propagation is based on a received signal bouncing off multiple surfaces and received from each of those surfaces at slightly different times. The walls, ceiling, floor, and other objects that are indoors result in increased multipath propagation indoor rather than outdoor. Conversely, when the device is outdoor, there may be a bounced signal, but generally the number of multipath signals is reduced. The network signals404that are used for detecting this multipath propagation may include Wi-Fi, GPS, cellular, or any other communication signals received by the device.

In other words, when a mobile device and its transmitter are both outdoors, the mobile device may likely receive at least two signals: a direct signal and a ground-bounce signal. The ground-bounce signal may take a path from the transmitter antenna to the ground, reflect from the ground, and then propagate to the mobile device antenna. Other reflections are possible, but are likely to be limited in number. Conversely, multi-path routes indoors may include multiple walls and the ceiling. Multi-path signals may contain more energy and carry a larger number of time-delayed signal replicas for the indoor scenario rather than the outdoor scenario. Multipath may be suppressed to reduce the communication channel's bit error rate (BER), but may be sensed prior to the suppression. A correlation circuit may be used to estimate the number of time-delayed signal replicas. The energy in a multipath signal may vary widely, based on whether reflections from surfaces are specular or diffuse, whether different signals interfere constructively or destructively, and whether any reflecting surfaces cause focusing.

Referring back toFIG. 5, the location state determination in block506may include a weighted algorithm for making the determination. The specific weights to apply to each sensed indicia (e.g. GPS analysis508and multipath propagation510) may be determined empirically, by collecting measurements in known conditions, and calculating weighting coefficients so that the combined calculation meets or fails a requirement, with some degree of confidence, according to the indoor/outdoor conditions. The user may be prompted to make a determination, if the sensed indicia do not provide sufficiently reliable determinations.

In alternative embodiments, the GPS analysis508may be performed first and the multipath propagation510is performed when the GPS analysis508is inconclusive. There may be a certainty level for the certainty needed for the GPS analysis. The certainty level may be referred to as a threshold. That certainty level may be based on the number of satellites detected. For example, two or more satellites may be outdoors and no satellite is indoors while one satellite may be uncertain to determine indoor or outdoor state. In other words, detection of one satellite may suggest an outdoor state, but is less certain than detecting two or more satellites. Alternatively, both the GPS analysis508and the multipath propagation510may be performed and the output weighted based on certainty. For example, when three or more satellites are detected, the GPS analysis508may be given significant weight for an outdoor state. Likewise, when no satellites are detected, the GPS analysis508may be given significant weight for an indoor state. Conversely, when two satellites are detected for the GPS analysis508, it may be given smaller weight as the deciding factor and the multipath propagation510may be weighted more heavily.

FIG. 8illustrates location state detection with a threshold for a GPS signal802wherein the threshold is called a first threshold. The threshold determination may be another example of the GPS analysis508. In one embodiment, the GPS signal802may be the GPS signal402described with respect toFIG. 4. The GPS signal802is received and the GPS signal802is compared with the first threshold804. The first threshold value may be a measurement of GPS signal strength. When the GPS signal802is below the first threshold, the mobile device is determined to be in an indoor state806. When the GPS signal802is equal to or above the first threshold, the mobile device is determined to be in an outdoor state808.

FIG. 9illustrates location state detection with a threshold for an A-GPS signal902wherein the threshold is called a second threshold. The threshold determination may be another example of the GPS analysis508. In one embodiment, the GPS signal402described with respect toFIG. 4may also be an A-GPS signal, such as the A-GPS signal902. The A-GPS signal902is received and the A-GPS signal902is compared with the second threshold904. The second threshold value may be a measurement of A-GPS signal strength. When the A-GPS signal902is below the second threshold, the mobile device is determined to be in an indoor state906. When the A-GPS signal902is equal to or above the second threshold, the mobile device is determined to be in an outdoor state908.

FIG. 10illustrates location state detection with a threshold for a multipath propagation signal1002wherein the threshold is called a third threshold. The threshold determination may be another example of the multipath propagation510. In one embodiment, the multipath propagation signal1002may be one or more of network signals404described with respect toFIG. 4. The multipath propagation signal1002is received and is compared with the third threshold1004. The third threshold value may be a measurement of communications signal strength for multipath propagation. When the multipath propagation1002is below the third threshold, the mobile device is determined to be in an outdoor state1008. When the multipath propagation signal1002is equal to or above the third threshold, the mobile device is determined to be in an indoor state1006.

The system and process described may be encoded in a signal bearing medium, a computer readable medium such as a memory, programmed within a device such as one or more integrated circuits, and one or more processors or processed by a controller or a computer. If the methods are performed by software, the software may reside in a memory resident to or interfaced to a storage device, synchronizer, a communication interface, or non-volatile or volatile memory in communication with a transmitter. A circuit or electronic device designed to send data to another location. The memory may include an ordered listing of executable instructions for implementing logical functions. A logical function or any system element described may be implemented through optic circuitry, digital circuitry, through source code, through analog circuitry, through an analog source such as an analog electrical, audio, or video signal or a combination. The software may be embodied in any computer-readable or signal-bearing medium, for use by, or in connection with an instruction executable system, apparatus, or device. Such a system may include a computer-based system, a processor-containing system, or another system that may selectively fetch instructions from an instruction executable system, apparatus, or device that may also execute instructions.