I didn't find any clear answer through my searching and I am wondering what is meant by :
Improves iBeacon connectivity and stability
I am interested into knowing what changed here. I guess it won't be much, but I'd like to know how good the technology may have improved.
How is the connectivity better? Is it monitoring/ranging related? Both?
Or does it have something to do with the device bluetooth connectivity? In what way?
In what way is it more stable? What is meant by more stable : a more precise accuracy for proximity detection? As it relies on Bluetooth Low Energy, could it really be better than is it now?
Those are a few question that are on my mind. I am going to try to have some testing on my side, but if someone did it already, I would appreciate to know the results!
I can answer the question related with the beacon stability.
When you range the beacons around, you parse their advertisement data, then identify them and get their signal strength. If
the signal strength (RSSI value) is same or almost the same for every range (search), then we can say that this beacon is stable. If not, it is not stable.
According to my experiments, it is not much stable but this can change according to different beacon types and other inputs like how often the beacon advertise (it is assumed that 10 times per second gives the best performance).
Related
I know that BLE RSSI values are based on decibel values but I was wondering if there was a way to convert this into a more meaningful value that I could use (even a float would be fine).
I've looked at Kalmon filters but I'm struggling to understand them. Any help with this would be appreciated.
With the limitations of the iphones and ipads' hardware I dont believe there is a method for getting more precise data from RSSI values. Perhaps if you say what you are using it for I can help advise an alternative route to solve your problem. I understand that it is difficult to gain qualitative information from RSSI values from Bluetooth LE, however, there are also other methods such as coupling different systems with Bluetooth LE that may produce the data you are seeking.
What is the best (meaning least power consumption) way to use some location based service in an iOS application? E.g. checking the position in the background every x sec/min.
I've read about geofencing, but I'm not familiar with it in detail (how often it is updating location etc.).
Thanks for sharing any ideas
There is no best practice, it depends much on your application, which location accuracy it needs. How fast you need a position change, etc.
Either you need to be accurate to under 30m then you need GPS, which uses Power (8h of recording is possible at best location quality without using the phone otherwise)
Or you need much less accuracy, typically 1km, then it works with Cell Tower or Wifi location, which uses less power.
In between there is nothing reliable. (e.g 100m accuracy with low power, does not really exist, at least I would not trust such a setting, there are no published measurements how accurate an iphone really is in the lower accuracy settings).
I am very confused about the meaning of the core location constants. For example for my app I would like to get accuracy readings within 100 meters and it looks like kCLLocationAccuracyHundredMeters would be the appropriate choice. However with this settings I often get points with accuracy worse than +- one thousand meters and when I disable wifi. Are these core location constants only relevant when wifi is enabled or does it sound like I am doing something wrong? It seems weird that Apple wants developers to not have to worry about the underlying hardware (i.e. whether it is using gps, wifi, or cell towers) but have the accuracy totally depend on wifi being enabled.
Thanks for your help.
GPS readings depend on a LOT more than just your accuracy setting. For example if you are not using wifi and you try to take a reading from indoors I have seen GPS be several thousand meters off consistently until you go outside. If you are planning on making your app accurate for indoors I would not plan on relying on the typical GPS. If your major use case is outside than GPS is VERY accurate.
The accuracy constants are how you "request" a specific accuracy. What you actually get depends on what is available. CL will try to give you your requested accuracy (or better) but it will give you what it has even if it is worse accuracy while it is trying to get better accuracy location.
If you wait long enough (and ignore the locations that aren't good enough) then you will eventually get better accuracy location unless it can't be done (such as when GPS satellites aren't visible or there is no WiFi, etc).
Is there a way that I can determine a location of a laptop/phone connected to my router via a wireless network access point? (I do not want to use GPS... only the access point).
No. But let's examine why.
If you can get the metrics from the router, which might or might not be possible, you can get the signal strength. This will give you a circle. But, this is limited, as you also need to know how strong the WiFi card is to determine rough distance. But, you probably know the rough distance your router works under, or the max circle, so this is not very useful.
If you have more than one access point, however, you can use triangulation. With two, the information is limited; three or more will give you a more accurate distance and allow you to extrapolate the strength of the signal.
Nope. You might be able to estimate its distance away, but even that is not likely if you're inside a building. Various building materials attenuate the signal, so the response is non-linear. If your router has two separate antennas, and you can measure the signal strengh from each independently, then you might have a chance of getting a feel for the direction, but I doubt the signal resolution will be high enough to give you any meaningful data.
Yes. However you'll need more than one Access Point and some serious software.
There are a number of solutions available and in-development for Location Based Services in Wi-Fi Networks. As Gregory mentioned above a single AP is not enough to do anything but poor range estimation, however multiple APs do not typically use triangulation to determine the location solution, they use a trained Hidden Markov Model.
A general question: is it possible to retrieve information about how far away e.g. a computer is from a wifi-router. For instance I want to get data on my computer if I'm 10 meters away from my home-wifispot or 2 meters.
Any idea if that is even possible?
Edit: How about bluetooth? Is it possible to get information about how far away bluetooth-connected devices are one from another?
I would recommend a measuring line or just good-old-fashioned guesstimating.
There is no "simple" way to do it (complex ways may involve building "accurate" signal maps ahead of time or trying to fit a better equation which is still subject to anumber of the limitations with the naive rule) and the rule of thumb "1/r^2" is just that -- a general rule of thumb. On the other hand, perhaps there is some existing software that will show you your RSS strength and make the task feel accomplished :-)
You will find useful links if you google for "RSS signal distance". This kind of task seems quite a common topic in academia w.r.t. small wireless devices ("motes") as well and there have been some interesting approaches to this problem such as the fitting of secondary low-frequency acoustic sensors.
You can query the signal strength which is some kind of indication of distance and obstructions and a few other factors all rolled into one measure. With just plain wifi though this isn't possible directly.
Try measuring the response time of the router to pings, with the data rate set to constant to avoid that effecting the response time. Take lots of samples and remove outliers to reduce errors, but you will still have a substantial quantization error. Subtract the latency of the router and computer, divide by 6 then multiply by the speed of light and hopefully you will have the distance to a resolution of a few metres.