I know its probably possible, but is it practical and doable to try and geo-position someone using WiFi to triangulate...
Thinking if I was underground and didn't have access to GPS, could I setup WiFi spots around the place to help locate someone.
Or if I was on a plane or a train (which is constantly moving), could I setup WiFi spots around the place to help locate someone.
Where would I start in doing this? Is there software components/infrastructure? If not would it be possible to do this... i.e. at a router level add location information to the packets about which router the incoming message was coming from and then the server being able to pick up on this...
This is exactly how the Skyhook database (built into many phones) works. It uses cell towers and WiFi points to triangulate the position in the absence of a GPS signal.
Google also does this with their street view vans—they look for open wi-fi networks as they go, and record their positions.
This is already widely available. Google the terms wifi location aware.
This is how laptop "Lo Jack" theft recovery systems work, for example.
Related
I want to create a mobile app which can connect to devices having the same app installed without having a server in between. The devices should act as server and client and discover nodes similar to them , like how it happens in block chain?i firstly want to know the discovery protocol that how these devices will discover each other . I have seen the samples of sockets , TCP connection but they know the ip address before , in my case we donot know the ip address , have to discover similar nodes also with security like cryptography happens in block chain so , random device don't mess up with my chain
I am starting to learn about it, and one of the first things that came to my mind is RPC, because is how Bitcoin works: link, and you can check also de P2P section in the link.
I will follow this and update my answer with the things I'll find.
Good luck.
I'm trying to come up with a way to sync a sqlite database between two computers.
If this were on a machine with a public IP this would not be difficult but I'm trying to find a way to make this work for ANY two devices, and most computers don't have a static IP.
What are some of the ways I can tackle this problem?
Assuming you just need to find the peers IP address...
Broadcast a Udp packet onto Lan, if machines are same lan segment. You can also try using admin scoped multicast, but mileage will vary according to the network setup and gear in use.
If trying to find two machines across the internet (assuming you can solve the NAT address translation issue), you need to bounce off a node that will hold info for you. Eg write a packet to dweet.io or sparkfun or other website that will hold store and forward data. You can also read twitter feeds etc, basically you need a known reference point to both talk too. Look into how malware create command and control networks for some ideas. Or search for rendezvous servers and protocols.
If the address range is small, probe all possible addresses. But be careful as you might trigger anti virus or ISP action
If wanting more browser based, look at webrtc, not quite what you are after but some of the techniques for discovery might be interesting.
If you have access, you can play with your DNS records. Essentially this is a variation of (2).
There are more options too, but that get more special purpose or become a bit too stelthy for general use. Also see how mesh networks are formed.
I am trying to establish a wifi connection between iPhone and another ARM device(as AP), and thanks to NEHotsportConfiguration added in iOS11, the connecting process becomes easy and quick and all I need is AP's ssid and password which will be transmitted via BLE, Of cause they must be encrypted. now here comes the question if it's possible to use WPS instead of transmitting password in air.
I have read something and given my own answer No, so please correct me if have any mistakes, thank you.
No. No version of iOS or OS X supports WPS because it has fundamental security flaws that cannot be readily fixed. More to the point, you should disable WPS on any router that does support it, because it is a security hole so big you can drive a truck through it.
For more information, see:
https://apple.stackexchange.com/questions/81994/is-it-possible-to-connect-an-iphone-ipad-via-wifi-protected-setup-wps
and
http://routersecurity.org/wps.php
I have a client that has an industrial space. In this space they have automated machines that move up/down, sideways, forward/backward, and raise completely by swinging the machine’s bottom upward. To control these devices they have a large system box with relays that basically tell which switch to activate. This control box is in the center of the industrial space. What they want is to store all the logic and system files in the “control center” box (that is located in the middle of the space) and then have the ability to operate individuals machines, or several machines either, all together or synchronously, while personally moving around the space. After talking with them, they are keen to the idea of us developing a Wi-Fi based interface in the Control Center, and then be able to use a mobile device (phone or tablet) to communicate with it. The Wi-Fi and mobile app concept is easy enough to write, the issue is that they have two concerns: Personal Safety, and Security of the network.
For personal safety, they need it to be that the mobile device cannot connect or operate the equipment if the user is NOT in the same room, or space. Meaning, they cannot push a button on the tablet, walk away or out of sight and not see if a machine is crushing an employee, or an employee is not playing around and dangling from the equipment. So they have to actually be within eye sight in order to watch for safety.
For security, they want to be able to connect to the Control Center through Wi-Fi, and operate the system. They do not want other people with smart devices or laptops to be able to access, hack it, and see the addresses and so on.
I was originally thinking of using GPS satellites and establish GeoPolygon (GeoFence), using latitudes and longitudes, to map out the perimeter of the industrial space. Then with that, when the user enters or exits the space the GPS would trigger a push notification (like a foursquare check-in), and disable/enable Wi-Fi connections, and thus letting the user know that Wi-Fi is either on or off and they can or cannot access the control center to operate the machines.
The problem I found is that GPS can be unreliable, especially indoors, in cityscapes, or when there is a lot of frequency static or interference.
So, to finish my long story, I was wondering if anyone had any plausible ideas as to how I can toggle Wi-Fi access on or off based on the user’s location and when the user is moving in or out of the fixed-location space (ie. wharehouse)?
GPS does not provide 18 inches of accuracy.
Indoors, GPS probably does not work at all, or with errors of 30m or more.
Outside 3- 6 m is normal, in cities up to 30m error happend evry day, too (in a 20 minute trip driving home, passing by houses with height of 18m left and right of the road.)
Wifi also works for higher distances, you cannot get the distance to the device.
What you probably need is another thing:
NFC: Near Field Communication
Till the current Iphone 5, NFC is not supported.
Maybe next generations or some Android phones.
At least you now know what does not work.
I heard about wallpaper made for blocking wifi connection, maybe you can put this wallpaper inside the rooms and make more networks, so only person inside the room can control this room, than connect that wifi modem with cabel to some network controll PC and throught it you can control remotely also that room.
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I am looking to develop an application usable on the devices of visitors so that I can tell where they are. The initial idea I had, already done in some museums, is to have a number on specific locations within the museum, they call a phone number, enter that number, and get enhanced content, perhaps audio narration about that space. This is nicely device agnostic, though some WiFi only devices may not have a mechanism to call a phone number, but perhaps having folks on WiFi load a mobile website and choose their location (assuming the number of spots is not too many) from a list, and then click a button.
I'm new to this, and have been brainstorming on this, but I really don't know what I don't know. So here are my questions:
Can I use GPS indoors and get accurate information or will that basically not work in most buildings?
If I use a service like Skyhook Wireless, and use multiple WiFi routers, will I be able to locate the WiFi connected users accurately?
Can I use Bluetooth somehow? Setup for Bluetooth seems like a hassle, but maybe there's a Bluetooth mode that is simpler to use for an application like this?
For devices with a camera, what can I do with an image here. Photo of a QR Code? Are QR code reading libraries built into devices I can use, or would I need to find a library?
Are there are other techniques I might be able to use, maybe counting footsteps with the accelerometer somehow? Or using magnets somehow for devices with a compass?
Suggestions welcome, assume I'm trying to target as many smartphones as practical (Android, iOS, Blackberry, webOS, Windows Phone 7) that are popular in North America. If there is a way to also include devices that are not considered smartphones, that would be great too.
UPDATE
Why indoor navigation is so hard: Your phone can get you to the museum, but it can't guide you to the T-Rex by Nick Farina
UPDATE 2
Brooklyn Museum experiment with QR Codes: too soon to
tell/negative
Very few people can successfully scan and use a QR code
UPDATE 3
Think GPS is cool? IPS will blow your mind
QR codes are your best bet. They're cheap and, for example, in a museum you could put one next to every painting. For devices without a camera, you could choose to print a location-code next to the QR that they could enter manually in an app. Here's another solution as well:
Set up a wifi repeater/booster in each location you want to determine (ex: in a museum, each room) and record the SSID for each router. As the user walks from each room to the next, their device will automatically switch to the repeater with the highest quality signal (the one in that room). Simply have your application test for which SSID the user is connected to.
GPS is not accurate enough and may not work inside buildings and Skyhook wireless is only for one address. Having users call a number and/or go to a website to manually select a location is too many steps for the user, and the user may not have reception to place a call. Bluetooth is a huge hassle.
Can I use GPS indoors and get accurate
information or will that basically not
work in most buildings?
no, GPS needs a clear view of the sky. regardless, the accuracy of GPS is around +/- 50 feet and can be worse.
If I use a service like Skyhook
Wireless, and use multiple WiFi
routers, will I be able to locate the
WiFi connected users accurately?
aGPS is less accurate than GPS.
Can I use Bluetooth somehow?
bluetooth is not location aware.
android 2.3 introduces something called near-field communications. this would theoretically allow the person to wave their phone over a receiver and transmit information. it's quite new and i think the nexus s is the only device with hardware support for this. at best you are looking at some early adopter pain for that one.
Photo of a QR Code? Are QR code
reading libraries built into devices I
can use, or would I need to find a
library?
that's a good idea. QR codes are popular because they are simple. libraries are not part of the SDK but they exist. it would be hard to build one yourself if it came down to that. by the same token, you could just as the user to enter a simple location code. essentially the same thing and might be simpler than aligning the camera for a QR read.
it does depend on your application. if you want this to automatically locate everyone without an user intervention, QR codes / codes won't work because the user has to take some action. even NFC, from what i've read, operates on very short distances so the person would need to wave the phone across something closely not just walk by.
If you're talking indoors, I think you have some great ideas. GPS may be spotty depending on the building, and Wi-Fi triangulation only works if your signal is proportional to the proximity of the user to the unit. Here is my suggestion:
QR Codes sounds like the best option here if you don't mind having them all over the place. If someone can scan a QR code, (which they are on most all platforms, it's just making sure your users have a decoder installed and can actually use it), then you have three things going for you:
You know they have to be in range to scan it...so that's far more accurate than you can get with other location devices.
you can use the QR code to embed a link to a download site or embed the actual information into the QR code if it's not too much.
Most smartphones today have QR code scanner apps built in, and there are libraries (java and .net) that you could use to build your own app.
The downside here of course is that you're assuming the cameras are good enough quality and that someone isn't going to deface your QR code so that subsequent visitors can't read it.
Keep in mind the bump application. They don't use bluetooth or any form of wireless technique to determine if two people are near each other. http://bu.mp/faq
Since you have 1 building that you care about. Why not simply have a root device or network of devices in your building that you care about. This root device would communicate with all the clients to do your bidding.
Maybe cellphones can´t solve your problem, have you considered cameras on each room and a QR code tag on each guest? you might get the images from the security camera since they are infrared. Another way of achieving this is by locating the camera in front of the door so that the guests are always seen by the QR code algorithm.
Cellphones are just too diverse to implement this, have you thought that the guests might not have a cellphone at all?