Recent advances in wireless communications technology have created significant interest in the development of additional channels for communication over mobile networks. To be specific, in spite of its inherent business and technical challenges the peer to peer networking has become a popular research in mobility space. Though the current 2G and 2.5G cellular network does fully support peer to peer communication but the forthcoming 3G/4G do provide the required bandwidth required for peer to peer innovations.
The objective of this whitepaper is to give overview of peer to peer mobile communication over the existing mobile networks. In particular, we will be discussing the peer to peer social networking on mobile devices and its constraints as well as the pros and cons of P2P networking.
On analyzing the global internet traffic we observe that nearly 46% of the traffic is over HTTP followed by P2P which is at 37% which clearly indicates the significance of P2P network. Also there is strong growth in social networking by internet users. Globally top 10 most popular websites are dominated by these social networking sites like Facebook, MySpace, Live.com and others.
Though Social networking on the mobile hasn’t caught the attention of mass market as yet but as Google CEO, Eric Schmidt said, “The Internet is humongous. The notion of publishing and micro-blogging is an explosion that will drive networks further into everything we do and the confluence of three factors (computing, connectivity and the cloud) means your phone is your alter ego, an extension of everything we do. Our job is to make mobile be the answer to everything”.
So it’s not far before we start observing the coming together of P2P and social networking on mobile devices. There are numerous such scenarios where MP2P can be used, e.g.
- Michael has a Word document on his PDA that he needs to convert to PDF. He carries out a discovery activity and finds that someone in the vicinity is offering such a service. Michael sends his document, pays for the service, and receives the converted PDF document back.
- Danny is an affiliate for a music company. He receives commission when he sells MP3 files for them. Danny publishes his music selling service to devices in his vicinity
Some of these applications are mentioned below
- Fring - Using this application user can make free mobile calls. Users can IM with Skype, MSN Messenger, ICQ, Google Talk & twitter clients.
- iSkoot - This is the solution for Skype on the go. It’s an easy-to-use mobile application with all Skype features.
- SymTorrent - This is BitTorrent client for Symbian OS which supports downloading multiple torrents at the same time.
P2P Communication Overview
P2P File sharing
P2P file sharing systems account for a high percentage of the traffic volume in the fixed Internet, having exceeded http (www) or email traffic. The increasing availability of mobile data networks such as GPRS and UMTS in conjunction with attractive pricing schemes makes P2P file sharing an interesting application in the mobile context. But the operation of P2P systems in mobile environments encounters several problems, such as a relatively narrow and expensive air interface, highly varying online-states (presence) of the subscribers, a hierarchical network structure, and limited device capabilities.
IP masquerading is a form of NAT (Network Address Translation) which allows internal computers with no known address outside their network, to communicate to the outside. It allows one computer to act on behalf of others. The basic idea is to disguise the IP packets to or from the private network so they appear to the rest of the internet world as they originated from the gateway machine’s external IP address. The network address translator sits between the gateway machine and external internet. It changes the source IP address of the packet to the external IP address of the gateway. In order to keep track of the host on a private network from where the has originated it also assigns unused protocol port number on the gateway machine. Whenever response is received on that port of gateway, the translator knows to reverse the process of substituting the original IP address and port number within your private network.
Mobile P2P Databases
A MP2P Database is a system in which information stored on peers of MP2P network. The mobile peers communicate with each other via short range protocols, such as Bluetooth, Zigbee, IEEE 802.11 or UWB (Ultra Wide Band). These protocols support short range communication (10-100 meters). On each mobile peer there is a local database that managers and stores a collection of data or reports. Often report describes physical resource such as an available parking slot.
MP2P database concept is evolved basically to address the need of searching local information which may be temporary in nature i.e. valid for short duration.
Overall System Architecture
The Mobile peer to peer architecture is based on a layered architectural pattern where each layer is assigned with its own responsibility. By using the layered approach, the architecture would gain positive characteristics like modularity and transparency. The negative effect by using this approach could be slower execution if the applications often have to go up and down several layers to carry out the operations.
Mobile Peer to Peer Communication Architecture
- Client: A mobile client is a logical representation of a peer, i.e., creation of logical communication using mobile network.
- Network: A network layer representing the communication medium accessed by the Client and server architecture. The network layer carries data to server , and data to peer to peer mobile network.
- Message: A message is an entity that can be exchanged between the server and mobile nodes. A message can be sent to single nodes; it can contain text, serialized objects, or any data type or binary data such as pictures, video, documents etc.
- Presence service: A service is a description and an identifier of an application running the server. It enables peer to peer communication and updates the presence status to the connected nodes.
- Session: A session represents the lifecycle of all the communication between the mobile clients in a peer to peer communication. A session keeps track of known nodes and available network mediums.
- Application: A peer to peer application has various features like File transfers, Social networking, voice communication etc.
Challenges and Threats for P2P
Challenges in mobile networks
- P2P traffic should be kept local for fixed/wireless operators
- Asymmetric speed and P2P unattractive charging
- Variable terminal connectivity
- High signaling traffic in unmodified P2P systems
- Operators wish to participate in service creation
- Traffic volume
- Platform specific peer to peer communication
- Support for protocol communication
- Compression techniques
- File format & codec supports
- Managing the session
- Limitation over data transfers on existing cellular networks
- Delay in data transfers
- Push communication from server
Other challenges in existing mobile networks
P2P introduces new security concerns and can make existing networks vulnerable
P2P security research is still fairly young
Legitimacy - P2P technology has been tainted by its use in illegal file sharing and piracy
Lacks of applications – Currently file sharing applications dominate this technology usage. There are no other types of application available which makes use of P2P technology.
Threats to MP2P
In 3G true MP2P is possible due to high bandwidth, high end efficient mobile phones and simultaneous data and voice capabilities. But then the question is whether the operators will allow MP2P since it would lead to loss in their revenues.
Digital rights management.
Other threats are like spy, viruses and adware
Mobile Peer-to-Peer is an opportunity for the cellular domain but many challenges need to be first solved. The solution should be simple, but at the moment the DRM based proposals look often over engineered. To get a rich service set, it is an absolute necessity that the community has hands to develop mobile application across the platform(s). Operators’ role is to provide the secure network for the developers and consumers and also with higher bandwidth. Before that is a reality, cellular networks and devices must take giant steps with existing pattern.
It is however apparent that Mobile peer to peer networking will see an enormous growth in near future due to the increase in the amount of data being shared. This will be further supported by availability of higher networks speeds such as 3G and 4G.
Endeavour Software Technologies is an expert in mobile technology and advises startups, SMBs and enterprises in defining the right mobile application, selecting appropriate technologies, wireless carriers’ relationship, and establish innovative roadmap for the continuous success as the future technologies changes over time. Can be reached at www.techendeavour.com or firstname.lastname@example.org