Is it possible using WiFi or Bluetooth to know where the hotspot is ?
I mean, from my mobile, know the distance and the bearing to head to it.
A single and static phone can hardly localize a hotspot. However, it may be achieved by multiple phones which cooperate with each other.
Moreover, I believe that Google has a database with the rough locations of static APs identified by SSID or MAC address all over the world. The RSSI values and locations (got from GPS or cellular network) are reported to a Google server by Android OS periodically - I guess. So you can achieve your goal if you have access to that database.
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I am trying to build a system with a raspberry pi that allows clients access into a building depending on their membership status. Right now, it uses QR codes, but I want to know if it is possible to add a feature where it uses some technology like NFC or RFID or Bluetooth to detect their phone or RFID card from at least a foot away and confirm they have a membership.
Someone told me I could use RFID, but I am only aware of that being used in short-distance applications, like a card on a hotel door. I am not sure about Bluetooth either, because the phone would have to connect to the pi first, right? Maybe there is something I don't know about. So please offer any suggestions. Thanks
I think bluetooth does good work for tracking user. Since it's the best to handle large distances than NFC and RFID these two technologies are used for low range scenarios, check this link.
In addition, you can check distance(using Proximity and RSSI) and membership status as well. but you need to know how to handle bluetooth connectivity with raspberry pi check this link. as well create an app on that mobile phone to use Bluetooth (depending which OS you're using for Android, iOS).
Regards,
I have a number of required business cases for HoloLens that require the device to understand a general geolocation, such as the current wearer longitude and latitude within 10 meters or so, as well as sending location information to and from an endpoint during various processes. Users WILL have a mobile device with geolocation capabilities that could assist in the process if necessary, and could also be used as a WiFi hotspot.
Is this a reasonable and reliable use case for HoloLens? Can apps be created that use geolocation and maintain connectivity during an experience, either on their own or with real-time communication to and from a mobile device that has these capabilities?
Yes - definitely is a realistic scenario. I've done some integration between a blue-tooth GPS and the Hololens. Let me know the particular device you're looking at and I'll see if I can get it working with the Hololens. //Lance Larsen (Microsoft MVP) - www.lancelarsen.com
I'm not sure how to correctly phrase this question, as I'm just starting to learn Bluetooth and its ways, but... imagine holding in an iPhone or Android phone in your hand in a large building with many rooms. You pair your device with a Bluetooth master device via an antenna in that room. Then once you move from room to room, your device communicates with other antennas throughout the building, but the device treats it as one pairing.
Is this at all possible? Was Bluetooth developed with this in mind at all?
Would this still work if the antennas were wireless? My idea is for devices to communicate with nodes via Bluetooth, and nodes interact with central base via wi-fi/local router.
Also, third random question: how does using BLE affect any of this?
Please tell me if I'm crazy! Thanks!
Bluetooth 4.0 BLE allows for a slave to connect to one master. 4.1 BLE allows for more than one connection, but I don't know if anything implements that yet.
Either way, there's no sort of "roaming" method pairing devices like with wifi access points with the same SSID. BLE however doesn't require pairing like regular Bluetooth, so you could just connect to a new access point each time you lose a connection.
You can also communicate via advertising packets from the "antenna" in each room. This would facilitate information being passed from those rooms to the phone, but not the other way around. This is basically how you communicate with BLE when you don't pair/connect devices and is how iBeacons work.
If you're writing the software yourself, and installing it in the building and on the phone, then I think it should be totally possible. Bluetooth devices can detect the distance and direction of other bluetooth devices. So if both devices are running software that is designed to, and grants permission to do so, it should be no-big-deal to programmatically auto-reconnect to the new nearest antenna whenever one becomes significantly closer than the one that your phone is currently connected to. As for software that already does this that you wouldn't have to develop from scratch yourself, no idea.
I am Developing a Java ME Application. Here I am using WiFi Connection. Now My Question is how to get a particular WiFi Connections name using Java ME Code ?
My Requirement is for Nokia E5 Device only.
After doing much research work I found that this is not possible in Java ME Technology to fetch the WiFi Connection's Name.
However Similar Library would be com.nokia.multisim.networkid which returns Network ID and Network Short Name.
I Dont Think so it is 100% possible in J2ME and even though if it has worked and there is no guarantee that it will work on all J2ME devices which has Wifi connectivity.
most appropriate answer i have found , please go through it once.
" Much as I hate to put you through all that grief and then not have a simple answer, I don't have a simple answer.
The reason for that is because Java's networking model is based on TCP/IP, and the TCP/IP architecture is based on the idea that applications will neither know nor care about the hardware details of networking. A typical mobile device may contain several different network interfaces (WiFi, Bluetooth, Infrared, USB cable, and so forth), but when an app wants to contact another network node, the app doesn't know which of these interfaces is actually being used. And in fact, if the OS wants to do so, it can use more than one (in parallel) and/or switch interfaces in and out, based on routing criteria such as best measured data rates. Rather like how cell phones route phone calls.
So basic Java/JME won't know anything about WiFi.
However, there is an extension, specified as JSR 309 (http://jsp.org) that looks like it may help. It supports learning about and controlling the network interfaces themselves. The problem is that not all devices will implement this extension, so it will depend on what device(s) you are supporting. "
I'm building an application where a mobile phone with an accelerometer is used to control an app on a computer in a similar way you would use a mouse. So I need to send the movement from the phone to the computer over some wireless protocol. I am thinking about using Bluetooth but I am not sure what transfer delay to expect. Another possibility is using 802.11g. What do you think? What delay could I expect given that I don’t hit the bandwidth limit?
I worked with a group at Motorola who linked up an external accelerometer pack to a mobile phone using Bluetooth. This work supported a mobile games development class at USC's GamePipe Laboratory, and the speed was sufficient to control the mobile games developed by the students. You'll need to make sure your handset's Bluetooth stack has the correct profile enabled to allow data communication.
Another advantage of Bluetooth over 802.11g is that the frequency hopping Bluetooth uses will make it less vulnerable to interference by all the other 802.11 devices in the vicinity, which sit on one frequency.
I wouldn't expect the amount of data sent by an accelerometer would give Bluetooth any problems.