Dynamic Multicast Distribution Trees for mmWave Wireless Mesh Network (WMN) Backhaul

Network densification as well as new higher frequencies are seen as a solution to meet the capacity promises of 5G. However, this will mean much more frequent handovers and thus challenges for mobility management (MM). New MM schemes are being developed to allow rapid transmission / access point (AP) selection and make handovers more efficient. However, many of these schemes lay an extra burden to backhaul (BH) layer by generating additional traffic or tightening delay budgets. One possible solution is to use multicast type of traffic delivery and BH network that supports efficient multicast distribution. In this paper, we sketch out how MM mechanisms can utilize transport layer multicast and identify requirements for multicast support. Then we propose how our mmWave WMN concept can be used to implement such support, and describe instant multicast group creation and distribution mechanisms. The main idea is to utilize the underlaying multiple spanning tree based routing to facilitate multicast distribution trees. With a specific multicast frame header, the multicast groups can be modified without any distinct signaling messages. This enables frame-by-frame changes in distribution trees but also controlled group management is supported to avoid excess flooding.