Published/Subscribe in mobile ad hoc networks
Publication Date: 2016-Jan-13
The IP.com Prior Art Database
Emerging networking models such as mobile ad hoc networks allow mobile wireless/bluetooth devices to connect to each other in an ad hoc manner when they come within range of each other, and disconnect when they move out of range. Mobile ad hoc networks do not require, and cannot expect, any fixed infrastructure to operate. This poses a problem for publish/subscribe type applications which typically rely on a broker or a known publisher at a fixed address. This article describes an approach to solving this problem using minimal broadcast and point-to-point communcations to manage and maintain subscriber connections to publishers in a mobile ad hoc network.
Page 01 of 3
Publish/Subscribe messaging is a long-standing technology that allows one-to-many message transmission. Publishers "publish" messages that are consumed by zero or more subscribers.
A messaging network that supports publish/subscribe typically involves one or more brokers that maintain the relationship between publishers and subscribers. Publishers connect to a broker and register a "topic" that identifiers the type of message it will publish . Subscribers likewise connect to a broker and register their interest in messages published on a given topic. A topic is effectively a name space. As messages are published by publishers, the broker receives and forwards same to registered subscribers (if any) based on topic. A publish/subscribe network may involve multiple brokers which coordinate message distribution among themselves so that a publisher connected to one broker can publish messages to subscribers connected to other brokers.
An alternate method is a simple multicast. This method allows subscribers to connect to known publishers, e.g. via a predetermined ip address and port number, and subsequently receive message publications by the publisher.
As networks evolve, new networking models emerge, such as mobile ad hoc networks. These networks allow mobile wireless/bluetooth devices to connect to each other in an ad hoc manner when they come within range of each other, and disconnect when they move out of range. Mobile ad hoc networks do not require, and cannot expect, any fixed infrastructure to operate.
This is problematic for publish/subscribe messaging, where the presence of brokers cannot be guaranteed, neither can predetermined addresses of publishers, or where a publisher is simply unknown ahead of time. Publishers have no immediate means to find subscribers and vice versa.
Although a system based on broadcasts can be used for publishers and subscribers to find each other, flooding a network with unnecessary broadcasts is itself problematic. What is needed is a method that allows publish/subscribe messaging on a mobile ad hoc network or similar, that minimises broadcast traffic, and network traffic in general.
One solution for publish/subscribe messaging specifically in mobile ad hoc networks, that has the further advantage of minimising associated network traffic, involves six interrelated processes:
1. Broadcast publication availability
2. Response to publication availability
3. Broadcast of subscription request
4. Publication to known subscribers
5. Response to publication
6. Maintenance of active subscribers
//Subscribe in mobile ad hoc networks Subscribe in mobile ad hoc networks
Page 02 of 3
These processes, as described below, allow publisher/subscriber applications running on mobile devices in a mobile ad hoc network to find each other such that publishers can publish messages to interest subscribers, and subscribers can consume those publications, without relying on any brokers or fixed publ...