TECHNICAL FIELD

The present disclosure generally relates to generating a cross-personal area network (PAN) path based on stitching between border low power and lossy network (LLN devices).

BACKGROUND

This section describes approaches that could be employed, but are not necessarily approaches that have been previously conceived or employed. Hence, unless explicitly specified otherwise, any approaches described in this section are not prior art to the claims in this application, and any approaches described in this section are not admitted to be prior art by inclusion in this section.

Low power and Lossy Networks (LLNs) allow a large number (e.g., tens of thousands) of resource-constrained devices (i.e., LLN devices) to be interconnected to form a wireless mesh network. Each LLN device in the LLN typically is constrained by processing power, memory, and energy (e.g., battery power); interconnecting links between the LLN devices typically are constrained by high loss rates, low data rates, and instability with relatively low packet delivery rates. Hence, LLN devices typically rely on a centralized entity such as root network device and/or a path computation element (PCE) device to establish numerous Internet Protocol (IP) based routing paths for the LLN devices within a PAN, for example based on establishing a Destination Oriented Directed Acyclic Graph (DODAG) according to the Internet Engineering Task Force (IETF) Request for Comments 6550. Various proposals exist for optimizing routing paths in a DODAG in a manner that enables LLN devices to bypass a root network device which often can suffer as a “bottleneck” in the DODAG, described in detail for example in U.S. Pat. No. 10,749,786, assigned to Cisco Technology, Inc.

A fundamental problem in existing proposals for implementing a DODAG within an LLN is that any attempt for optimizing routing paths operate only within one routing domain, i.e., within only one PAN having a corresponding DODAG topology. Hence, peer-to-peer routing is not implemented across DODAGs, resulting in the necessity of all inter-PAN traffic to be routed via the root network devices of the respective DODAGs. Hence, a network can suffer limited scalability as a large scale LLN (e.g., a smartgrid) is split dynamically into multiple DODAGs, where inter-PAN traffic between DODAGs must be routed via the respective root network devices that can become “bottlenecks” for inter-PAN traffic.

