d broadband networks, the total capacity of the access medium (the fiber of a GPON or the wireless carrier of a cell site) needs to be statistically multiplexed across mul- tiple customer endpoints and devices. This requires some of the resource optimization and scheduling functions of a SDN to be carried out at the access node that is closest to the customer. The combination of distance constrained functions and shared media statistical multiplexing means that some of the functionality and software of cost-effective access networks must be distributed throughout a network close to the customer endpoints and devices, rather than being centralized in large data centers. Access networks also have functions that cannot be optimally run on normal mainstream com- pute and storage platforms, creating challenges for cost-effective virtualization. The input/output and communications protocols that are integrated into commercial compute platforms are designed for short-range high-speed point-to-point communications, such as connections from the compute node to the top-of-rack switch. Access networks require more complex and specialized real-time functions to support high-performance shared media, such as sophisticated transmit power control, variable range-compensating timing offsets, dynamic performance monitoring, dynamic error correction coding, dynamic modulation, and low latency request/grant resource scheduling. In wireline access networks, these functions are supported by dedicated system on a chip (SOC) integrated circuits with specialized hardware functions optimized for the specific requirements of each media and protocol. The functions in a typical wireline access SOC are only a starting point for the specialized hard- ware functions required for high-performance broadband mobile wireless access networks. Mobile wireless base station equipment is built around baseband signal processing, which utilizes massive amounts of digital signal processing. As spectrum auctions and valuations have repeatedly demon- strate