Device collaboration is a set of features that allows multiple devices under control of a single user to take advantage of capabilities of the other collaborating devices via a link between them, that is, a collaborative interface. For example, one collaborating device may hop through another device with better connectivity to reach a network service, or one device may access context or other information (such as address book information) on a peer collaborating device. A more specific example would include a Land Mobile Radio (LMR) device and a broadband device. Under non-collaborative operation, the LMR device is not able to access data services that are only available on broadband networks. Through collaboration, the LMR device is able to access broadband data services via the broadband device. More advanced collaborative features would allow user single sign-on (SSO) status to be shared among collaborating devices, or would allow a user to start an application on one device, and pause it and continue on another device.
Collaborative devices have a special relationship with each other in that they can be considered to be working together on behalf of a user. It would not be unreasonable to consider collaborating devices to be a single multiprocessor “virtual device,” with each processor connected by a wireless bus (that is, the collaborative interface). From a security point of view, this “virtual device” model is a good analogy because new and advanced collaborative features will demand the same type of security between devices that is expected over a single internal platform bus.
Personal Area Networks (PANs), such as Bluetooth (BT), are well suited for device collaboration communications. Because PAN technologies, such as BT, require a user to physically pair the devices (for example, via a Personal Identification Number (PIN) entry or a Near Field Communication (NFC) pairing), it is simple for a user to provide the necessary security needed for such a collaborative interface through the user's personal physical security. Further, BT allows for sophisticated inter-device security (with strong key derivation and device authentication) initiated only by the user touching the devices together (for example, when NFC is used).
However, instances arise when a user has a number of devices that are collaborating and sufficiently separates the devices such that they no longer can collaborate over the PAN. For example, a public safety officer may exit his car and leave one of his collaborating devices behind, traveling out of PAN range of the device in the car. For a variety of reasons, the user may still want to take advantage of the collaborative features of the device left behind.
One of ordinary skill in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Also, common and well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required.