I want to work with Wifi connection via Android Devices (for example I want to send a command with my device to home router via Internet and my router send this command to a wifi module) when I refer to Developer Android APIs, I see a section that named "Wi-Fi Peer-to-Peer". what differences exist between wifi (working android devices with access point like home router) and "Wi-Fi Peer-to-Peer". Is "Wi-Fi Peer-to-Peer" same wifi Direct ? why Google didnt discusses about simple wifi ? please help.
WiFi P2P (Peer-to-Peer) and WiFi Direct are both the same thing.
There are two main differences between "normal" WiFi and WiFi P2P (from the developer's point of view):
A WiFi p2p connection (something you establish from code) is a direct connection between two devices. You can understand it as a sort of temporary (created for the time of the connection) "normal" WiFi network created for the purpose of communicating those two devices. A "normal" WiFi connection basically translates to a situation when a device is connected to a broadcasted (by some device - e.g. home access point, or a smartphone) WiFi network. This all basically means that to send data between two devices using WiFi P2P, those devices DO NOT have to be connected to the same WiFi network (as long as those devices know how to connect to each other using wifi p2p). Unfortunatelly good news with WiFi P2P end right here, because:
Designing a WiFi P2P connection based system is extremely difficult if you want to make it at least reasonably robust. This is mostly due to the lack of documentation on that subject (in Android Dev), and due to Android's WiFi p2p unpredictability (I know what I'm talking about - I was recently desigining such system).
You're wrong saying that Google didn't discuss "simple" WiFi. You just need to remember that connecting to "simple" WiFi is just not that complicated, so they didnt have to do a guide like they did for WiFi P2P. All information considering "normal" WiFi are there (at Android Developer), its just spread over many classes.
Tell me what you think is not discussed?
Also you should try to describe the exact thing your application needs to do (with WiFi), so I can maybe give you a hint whether you should try your luck with WiFi P2P or not.
Related
So there's a requirement for an app that will communicate between devices if and only if its connected to the same local network.
E.G: Device A and Device B are connected to Wi-Fi network Z. The app will allow both the Devices to communicate between eachother (send messages/videos)
I've been researching the past couple of days but unable to get clarity with what I've found so far. (I'm confused between NSDManager, WifiP2pManager, etc. as to which one suits my requirement).
I just need confirmation between which concept/methodology to follow. Please help.
From my personal experience, WiFiP2PManager should do what you want. I have used it to connect two devices over the same WiFi network. It also allows your device to view all the other devices on the network and enables you to connect to them. Once you have connected to the device, you can then send messages across the WiFi network. This documentation does a good job of explaining how to use WiFi P2P and how to get started.
It also explains how to view devices on the network, how to connect with them, and how to transfer data. This should suit the requirements that you requested.
You can use NSD, but according to the documentation that is mainly used for giving your app access to services provided from other devices on the local network. It would allow your app to do file sharing with the other device by requesting a service.
After searching it up, I have concluded that WiFi Direct is the same as WiFi P2P. They both use the WiFiP2PManager.Here is a link for information about it.
You can use Network Service Discovery to find and connect to instances of your app. You can then open a socket connection to facilitate communication.
I created and example app on Android and on iOS that does this which I link to and explain in great detail here: http://brendaninnis.ca/connect-nearby-devices-part-2.html
I would like to make a game which takes place in the forest (around 2 hectares). The players(around 30) must have their phone connected to a router via wi-fi so that every players are connected to each others via LAN.
But I don't know how to make this possible.
Wifi mesh routers ? Helium baloon that spread wifi above the forest ?
Using Network Service Discovery you can achieve this. You need a wifi router to connect all the devices. One device will be a host and others will be a client.
Go through this link https://developer.android.com/training/connect-devices-wirelessly/nsd.html
The question is kind of broad, but here are my attempts at possible solutions
Have you thought about using wifi-direct between the devices? One possible implementation of this is to have a central router, some older phones/devices spread out in the forest connected to the router and eachother through wifi-direct. Then the players running around will be covered
"Wi-Fi Direct, initially called Wi-Fi P2P, is a Wi-Fi standard enabling devices to easily connect with each other without requiring a wireless access point.[1] Wi-Fi Direct allows two devices to establish a direct Wi-Fi connection without requiring a wireless router. "
https://en.wikipedia.org/wiki/Wi-Fi_Direct
If data is not an issue, and service is okay, probably better to connect them to a cloud through their regular data connections.
I have 6 android tablets, and i want to connect them via a cable/wire, so that they can send messages to one another. (perhaps similar to way PCs may be networked with each other)
Once connected, apps running on the devices can exchange messages with each other via sockets or any other protocol. What are the best options?
Connecting devices over wi-fi is an option too, but then internet is not guaranteed in this scenario, and devices may be very far of from each other for any near field communication.
You can use usb->ethernet adapters and connect via LAN
Connecting devices over wi-fi is an option too, but then internet is
not guaranteed in this scenario, and devices may be very far of from
each other for any near field communication.
as long as all your devices and server (if any) are on same LAN or simply everything is connected to same hotspot you need not to worry about internet
I am working around wifi direct and NSD (Network Service Discovery) to transfer files.
NSD: where serivce has been created and can scan the other devices which are publishing the same service with in the same network.
WiFi Direct: This is used to scan the near by devices without network
WiFi P2P Network Serice Discovery: This is used scan the service near by devices where other devices provide the same service (NSD+WiFi Direct)
As per requirement, I need to give compatibilty to iOS device even though both are not in same network. I came to know that NSD is similar to Bonjour service by iOS.But this can be possible when devices are in the same network.
Is there any way to get connect to iPhone when both are not in same not network?
Ignoring the intricacies of getting Android and iOS to play nice together, it is possible to make them think they are in the same network without physically being there. If I understand you correctly, seems like you have two options:
Setup up a VPN server in network A and the device in network B connect to it. This would make the device in network B think it was on network A, and have access to all LAN services (such as NSD).
Set up VLAN trunking on a switch and put network A in the same network as B.
Option 2 would only work if they were geographically in the same area (like on the same campus). Option 1 would be preferable if they were geographically disparate, or you were unable or unwilling to make the infrastructure changes necessary to support option 2.
Since I don't have an Android 4.0 device I haven't been able to test this myself. Also I wonder if connecting device A (a smartphone) to device B (a wifi direct capable device) using Wifi direct would mean that device A would assume it is provided with internet from device B (tethering?). I am trying to make an application for device A that would communicate with a device B that does NOT provide internet, thus it would be interesting to know if such a scenario would lead to device A losing internet connectivity for the duration of the connection. Is the situation different depending on if device A is connected to internet through an AP or through 3G/4G?
Perhaps using Bluetooth would be a solution, but in my case security is an issue, and it seems to me that Wifi direct provides stronger security (WPA2).
Any info would be helpful!
/S
On Android, Wi-Fi Direct doesn't interfere with your connection to the Internet (Wi-Fi or 3G/4G). A problem may be that once your turn on the Wi-Fi (to enable Wi-Fi Direct, your phone will try to connect to one of the saved available networks and will disable your 3G connection. That is because Android (by default) doesn't support dual connection (via both Wi-Fi and 3G/4G), but there is some applications around that claim that they can provide such functionality.