1. 802.11 MAC/PHY Introduction

Mango Communications 802.11 MAC/PHY Design implements a real-time 802.11 MAC/PHY in Xilinx FPGAs. The 802.11 design is an ideal starting point for developing programmable wireless systems that interact with standard Wi-Fi devices and to build a custom MAC/PHY based on 802.11.

The Mango 802.11 design is implemented as a combination of custom FPGA IP cores, bare-metal C code, and an optional Linux interface.

1.1. MAC Software

The 802.11 design implements the full MAC protocol in embedded C code which runs in dedicated CPUs in the FPGA. On Zynq MPSoC devices the MAC runs in the ARM R5 cores in the RPU. On other devices the MAC runs in MicroBlaze CPUs in the FPGA.

The MAC operates in real time. The MAC software is designed to support totally custom protocol implementations.

The MAC software design is split between the two CPUs in the FPGA design. The software project in each CPU is built on a MAC framework which implements the many building blocks common to multiple MAC designs. These frameworks are designed to simplify the development of custom MAC designs without restricting flexibility. The MAC frameworks are written in bare-metal C.

Fig. 1.1 Mango 802.11 MAC Software architecture

The reference MAC design implements:

• High-level MAC Applications

  • Linux Device Interface (linux_dev)
  • Access Point (AP)
  • Infrastructure Client (STA)
  • Ad-hoc Client (IBSS)

• Low-level MAC Protocols

  • 802.11 Distributed Coordination Function (DCF)
  • NoMAC - simple Tx/Rx passthrough template for custom protocol development

• MAC software frameworks

  • High-level MAC Framework - MAC support in CPU High
  • Low-level MAC Framework - MAC support in CPU Low
  • Common MAC Framework - Inter-CPU MAC support

1.2. IP Cores

The 802.11 design makes extensive use of the programmable fabric in Xilinx FPGAs. All real-time processing occurs in the fabric, including the Tx/Rx PHY and real-time parts of the MAC. The FPGA fabric is also used to implement interfaces to off-chip components like radio transceivers and other peripherals.

PHY and MAC IP Cores

• PHY Transmitter - real-time bytes-to-waveform transmitter
• PHY Receiver - real-time waveform-to-bytes receiver
• MAC Interface Core - real-time building blocks for MAC protocol implementations

Platform Support Cores

The PHY and MAC cores are designed to be platform independent. We provide a number of additional cores to implement a fully-functional 802.11 node on reference hardware platforms.

• AD9361 controller - manages AD9361 control interfaces
• User I/O Controller - manages user I/O on FPGA board (LEDs, switches, etc.)

1.3. Licensing

The Mango 802.11 MAC/PHY Design is suitable for a wide variety of applications and is available under flexible licensing options.

License Types

The License Type depends on the customer and application.

• Academic
  • Use and extend source code
  • Licensed to single site
  • Use for non-profit teaching and research
  • No re-distribution
• Commercial
  • Use and extend source code
  • Embed and distributed compiled design in products
• Custom
  • Tailor license terms for a specific application
  • Contact us to discuss your requirements

License Tiers

The License Tier depends on what source code access is required.

• MAC Software Source
  • SDK workspace with full MAC C source code
  • Target supported reference hardware
• FPGA Design Source
  • Includes MAC Software source
  • Vivado project with IPI design
  • Includes source for utility IP cores
  • PHY IP cores delivered as netlists
  • Target custom hardware
• Full Source
  • Includes MAC Software and FPGA Design sources
  • Adds source models for PHY IP cores
  • Customize and extend Tx/Rx PHY designs