Wifi direct protocol stack

It supports It is written in C, and can run on any hardware platform. An New : Application Interface Layer Provides the interface to the application to manage the networking connection, retrieve the signal and link quality information, and do a site survey.

Porting Layer Provides service functions related to the hardware, OS, and compiler. Due to the complexities of the There is no need for an Access Point. It is a protocol designed to replace the legacy ad-hoc IBSS protocol. Improvements over ad-hoc include easier connection and the latest security, The performance of a particular group of Wi-Fi Direct devices depends on whether the devices are A single device in a Wi-Fi Direct-certified group network may share internet connectivity with other devices in the network by creating simultaneous infrastructure and Wi-Fi Direct connections.

A network of devices certified under the Wi-Fi Direct program operates in a security domain separate from the infrastructure network, even when cross-connected. A Wi-Fi Direct-certified network can be one-to-one, or one-to-many. Connection to multiple other devices is an optional feature that will not be supported in all Wi-Fi Direct devices; some devices will only make connections.

Yes, the specification underlying the Wi-Fi Direct certification program supports operation in both 2. Devices operating in the 2. Not all Wi-Fi Direct-certified devices support both frequency bands, however, so you should check which bands your devices support.

Login Help. Remember Me. I have answered based on my personal experience. I have tried using wifi direct on a device which doesn't support I have never wrote such thing. And removing my previous remark won't change this fact. That's a hugely different statement. WiFi Direct is simply a P2P protocol and nothing restricts it to 11n. If a vendor binds these 2 things together, it's his proprietary decision. Official definition from WiFi Alliance: wi-fi. Show 1 more comment. Can you please tell if there a way in which I can make my wireless card make use of ath9k instead of ath5k both ath9k and ath5k are kernel modules — cgv.

Sign up or log in Sign up using Google. Sign up using Facebook. The channel method checks the status of the previously initialized channel and defines the messages to be returned to the application after the response of the wifiP2pService. Applications communicate with WifiP2pService to issues device and connectivity requests through the WifiP2pManager interface.

The methods of this java class are the different states of the state machine. The states implemented in the p2p state machine are presented in figure 4. We present here the formal specification of the groupCreatedState method which corresponds to the GroupCreatedState state.

To allow communications in the group, each device must have an address. The addressing of devices in the group is as follows:. The detailed study of the Wi-Fi Implementation on Android and the formal specification reveal that. Wi-Fi Direct is an interesting and suitable candidate technology for ad hoc communication in several applications, but his implementation on the Android OS has some limits on several levels relatively to the formation of a large scale Ad hoc network:.

In terms of connection and association: the scan, listen, and search processes may consume considerable amount of time in Wi-Fi Direct.

Two devices attempting a peer discovery can share probe messages only if a search phase and a listen phase is met on the same channel. However, these phases are randomized; as each listen phase of a device can vary from a random multiplier of time units.

Therefore, two devices could attempt multiple discoveries before actually synchronizing their channels, which could consume time in scales of seconds.

Moreover, this delay can be relatively high if several P2P Devices are simultaneously performing Device Discovery in the same wireless range. So each p2p group can only work on one communication channel. At the topology and mobility: In Android, upper-layer applications can specify a Group Owner Intent; otherwise the Wi-Fi Direct framework simply sets it with a random value.

The Group Owner election mode based on the Intent value is not optimal enough, since based on a single criterion. It can happen that after GO Negotiation, equipment having reduced performances becomes Group Owner at the expense of another which has higher performances. Once the group is created, all communication goes through the Group Owner.

Clients cannot communicate directly without pass to the GO. So the GO acts as a router within the group, but he cannot communicate simultaneously with Clients that are belonging in the group. Moreover, the number of devices that can be associated in a P2P Group depends on the maximum number of discovered peers the GO can remember, which limits the scale of the group and if the GO is leaving the group, the group is destroyed making the GO the central equipment of the group.

At the addressing and routing: In Android devices, once a Wi-Fi Direct connection is established, the Group Owner will always have This method of assigning addresses can cause conflicts in case the Group Owner is part of several groups. The Wi-Fi interfaces of the Group Owners that act as legacy clients in another group are assigned an IP address in the format Similarly, Peer to Peer interfaces of clients are assigned different IP addresses in the format This provides the address conflicts for Peer to Peer interface of the Group Owners.

Thus even if there is a way to allow multi-group membership, the devices in different groups may not be able to reach each other especially since no routing mechanism is defined. The protocol has also the potential to be used in several applications such as files transferring, sharing resources, online gaming, alert dissemination, social networking, etc. Most of research work is focused on the performance evaluation Wi-Fi Direct.

Providing efficient group formation techniques and supporting multi-hop communication are part of the key research issues highlighted in the literature. In this paper, we presented a technical overview of Wi-Fi Direct technology on Android in order to well understand its implementation.

We took out the layer structure of the Wi-Fi Direct framework on Android by presenting the different classes and their interactions in each layer.

We showed how the WifiP2pManager class works for discovery and connection to peers. We provide also the formal specification of some classes by using Z and Object-Z specification languages. Which leads us raise the limits of Wi-Fi Direct implementation on Android in terms of the development of large-scale networks.

These limits are of several orders: in the connection and association, in topology and mobility and in the addressing and routing. Asif Khan, W. Cherif, F. Filali, and R. Camps-Mur, A. Garcia-Saavedra, and P. Conti, F. Delmastro, G. Minutiello, and R. Je, D.

Kwon, H. Kim, and H. Kanaoka and Y. IEEE Sun, C. Yang, S. Jin, and S. Han, K. Lim, and Y. Feng, Z. Liu, and Y. Yoo, S. Kim, S. Lee, J. Hwang, and D. Lim, Y. Seo, Y. Ko, J. Kim, and J. Lim, W. Jung, and Y.

Camps-Mur, X. Zhang, Y. Wang, and C. ACM, , pp. Botrel Menegato, L. Souza Cimino, S. Delabrida Silva, F. Medeiros Silva, J. Castro Lima, and R. Oliveira, Dynamic clustering in wifi direct technology, in Proceedings of the 12th ACM international symposium on Mobility management and wireless access. Shahin, and M. IEEE, , pp. Arnaboldi, M. Campana, and F. Laha, X. Cao, W. Shen, X. Tian, and Y. Khan, W. Cherif, and F. A Shahin, and M. Cherif, M. Khan, F. Felali, S. Sharafedine, and Z.

Lombera, L. Moser, P. Melliar-Smith, and Y. Park, J. Park, and M.