The Mobile Triangle, depicted below, defines the pathways by which a mobile worker can stay connected, maintain his/her information base, and merge the information highway with the paper trail. It provides a mechanism to meet the mobile worker’s requirement to create hardcopy from his/her mobile information base.  

Information Access and Storage

The corners of the triangle represent points of information access or storage:

• The Enterprise Server: Repository of Mobile workers data and information including document, e-mail, calendar and address book.
• Mobile Digital Assistants: Devices providing mobile worker access to his/her information and data including mobile phones, palm sized and hand-held computers.
• Hardcopy Input/Output: Devices which extend the portability of the mobile worker’s information by providing a means to print information maintained in the Mobile Digital Assistant of Enterprise Server, or scan hard copy information received from others into the worker’s information base.

Communication Paths

The sides of the triangle represent communication paths between and among devices and information content:

• PCS, Wireless and Modem: Enables the Mobile Digital Assistants to synchronize information with the Enterprise servers. This includes assuring calendar and business cards are current, receiving new incoming e-mail, and sending e-mail created on the mobile devices.
• Local and Ad Hoc Network: Allows Mobile Digital Assistants to seek out and use a local hardcopy device. These devices might be in a hotel business center or storefront copy center. This communication channel may be peer-to-peer with the mobile device communicating directly with a printer using Infrared, or other communication technology. This channel may be a wired or wireless connection to a gateway into the local network, with the mobile device communicating through the gateway to a local print server or to the hardcopy device. This is a bi-directional channel, allowing information to be passed from a scanning device to a mobile device.
• Intranet/Internet: Enables Enterprise Servers to seek out and find Hardcopy Input/Output devices. The hardcopy devices may be on the Enterprise Server’s local network or they may be in a remote location accessible to the mobile worker.

Clearly, the Local or Ad Hoc Network leg of the triangle provides a path for the mobile worker to print information contained on the mobile device (depicted as path 1 in the figure). The more difficult, yet necessary cases involve a two-legged transaction.

• The mobile device is used as a conduit between the Enterprise Server and the Hardcopy Input/Output device (See path 2 in the figure).
• Using the mobile device, the mobile worker requests the Enterprise Server send a document to the URL of a specific hardcopy device (See path 3 in the figure).

Service Discovery is the Key

In all cases depicted by the Mobile Triangle, service discovery plays a key factor in every transaction.

Path 1

The mobile device uses service discovery to locate a printing device meeting the printing needs. Again using service discovery, the device driver is located and loaded for the selected printing device. Printing commences.

Path 2

Once again, service discovery is used to select a device and locate its device driver.  However, if the Local or Ad Hoc protocol does not use the same service discovery protocol as the PCS, Wireless or Modem protocol, an incompatibility may exist, preventing the necessary discovery.

Path 3

Service discovery is only used between the Enterprise Server and the hard copy device. Here service discovery is NOT used to locate the device, as the mobile worker has provided the URL. However, service discovery is still needed to determine the capabilities of the selected hardcopy device, then locate and load its device driver. If the hardcopy device is required to support a specific service discovery protocol for the Intranet/Internet leg (e.g., SLP) and a different protocol for the local, Ad Hoc leg (e.g., Bluetooth SDP), the manufacturer of the hardcopy device will face significantly increased implementation costs.

The Mobile Triangle Solution

Salutation is best suited to be the service discovery protocol for the Mobile Triangle as it is independent of the operating system and transmission protocol. Therefore, a manufacturer need only support one service discovery technology even if the device supports multiple transmission protocols. Additionally, no service discovery incompatibilities exist if one corner of the triangle is being used as a gateway between two others.

Back to home page