Renesas offers software stacks for a variety of sub-gigahertz (GHz)/Wi-SUN wireless communication applications.

Software for Renesas' sub-GHz wireless communication solutions use internationally standardized Wi-SUN profiles (Route B, FAN, HAN, and Enhanced HAN) on the Renesas RX651 microcontroller + RAA604S00 set or on the RL78/G1H microcontroller to provide stacks. The software undergoes interconnection testing by the standardization organization, the Wi-SUN Alliance, so you can carry out system design for a wireless network with peace of mind.

The software undergoes interconnection testing by the standardization organization, the Wi-SUN Alliance, so you can carry out system design for a wireless network with peace of mind. Choose from among three packages according to the needs of your

RF Driver PackageMAC Stack PackageIP Stack Package

RF Driver

The RF driver is a program that controls the RF transceiver and offers a PHY layer-level API (tables 1 & 2). It carries out 50 or 100 kbps GFSK-modulated wireless communications in the IEEE802.15.4g wireless frame format. It also provides functions such as carrier sensing, which detects surrounding wireless conditions to avoid collision with transmissions from other wireless stations.

 

This RF driver is not OS-dependent, and can be adapted to a variety of systems. However, a transmission control function for the user's application must be implemented in order to obtain technical standard conformity certification and construction design certification for wireless equipment under the Japan Radio Law. Transmission control stipulated by the ARIB STD-T108 standard for 920 MHz wireless equipment used in Japan is also implemented. For example for ARIB STD-T108, for a carrier sensing time of 128 microseconds and 20 mW output or less, the maximum total transmission time is 360 seconds per hour. This solution satisfies this condition by keeping track of accumulated transmission time and controlling transmission accordingly.

 

Table 1. RL78 Family sub-GHz RF driver

Software RL78 Family sub-GHz RF driver
Part number -
Status Available*

 

Table 2. RX600 Series sub-GHz RF driver

Software RX600 Series Sub-GHz RF driver
Part number -
Status Available*

*To request this software, please contact a Renesas sales representative or sales office.

MAC Stack

The MAC stack (tables 3 & 4) offers the MAC functionality stipulated by the IEEE802.15.4-2011-and IEEE802.15.4e-2012 specifications. IEEE802.15.4e-2012 includes a variety of optional functions. This MAC stack supports the functions that are necessary for realizing the IP stack which will be mentioned later and the mesh network.

 

Functions supported by this MAC stack

  • Wireless frame transmission and reception in non-beacon mode
  • CCA and CSMA-CA
  • Acknowledge frame transmission and reception, data re-transmission
  • Network scan and beacon frame response
  • Indirect transmission to sleeping device
  • MAC security
 
This stack supports MAC security functions. A security counter is used to avoid replay attacks and perform tamper checking, and 128-bit key length AES is used for encryption. An AES encryption processing program optimized for RL78 or RX microcontrollers is used to speed up processing.
 
This stack runs on Renesas μITRON. Communications protocols often require real-time processing and event processing for each layer. It is also useful if memory can be managed flexibly for processing transmitted and received frames. When μITRON is used, it is not necessary to consider the effect on real-time processing of the protocol stack portion when creating the upper-level application program. Future function expansion is also easy with μITRON.
 

Table 3. Wi-SUN ENET-MAC protocol stack for RL78 Family

Software Wi-SUN ENET-MAC protocol stack  for RL78 Family [CA78K0R]
Part number

 

RTM0RL7800NWSN0EM0JF
Status Available*

 

 

Software Wi-SUN ENET-MAC protocol stack for RL78 Family [CC-RL]
Part number RTM0RL7800NWSN0EM1JF
Status Available*

 

 

Table 4. Wi-SUN ENET-MAC protocol stack for RX600 Series

Software Wi-SUN ENET-MAC protocol stack for RX600 Series
Part number RTM0RX6000NWSN0EM0JF
Status Available*

*To request this software, please contact a Renesas sales representative or sales office.

IP Stack

In Japan, standardization of communications specifications, especially for smart meters, is proceeding in the industry. Standardization applies to a variety of services being born from the deregulation of the electric power industry, and aims to make power usage more efficient.

Example of Sub-GHz Wireless Network

 

In particular, for the communication path between smart meters and HEMS, called route B, major electric power companies have adopted the ECHONET Lite specifications for the application layer and sub-GHz wireless communications or power line communication (G3-PLC) for its communication layer. Specific specifications for sub-GHz wireless communications are stipulated by the JJ-300.10 standard from the Telecommunication Technology Committee (TTC). Renesas has been working on developing a communications stack based on the A method of JJ-300.10 (specifications from the ECHONET Consortium and the Wi-SUN Alliance) from the start, and offers its efforts as an IP stack (tables 5 & 6).

 

This IP stack supports 6LoWPAN, IPv6, ICMPv6, UDP, and other IP-based functions. PANA (Protocol for Carrying Authentication for Network Access) is supported for security for authentication, key generation, and so on. Although PANA requires relatively heavy processing such as hash calculation, a calculation library optimized for the RL78 or RX63N microcontrollers can be used to, for example, achieve route B communications processing performance even when operating an RL78/G14 at 8 MHz.

 

 

Table 5. Wi-SUN ENET-IF protocol stack for RL78 Family

Software Wi-SUN ENET-IF protocol stack for RL78 Family [CA78K0R]
Part number RTM0RL7800NWSN0EV0JF
Status Available*
Software Wi-SUN ENET-IF protocol stack for RL78 Family [CC-RL]
Part number RTM0RL7800NWSN0EV1JF
Status Available*

 

 

Table 6. Wi-SUN ENETE-IF protocol stack for RX600 Series

Software Wi-SUN ENET-IF protocol stack for RX600 Series
Part number RTM0RX6000NWSN0EV0JF
Status Available*

*To request this software, please contact a Renesas sales representative or sales office.

Dual Stack

In Japan, HEMS (Home Energy Management System) devices that carry out energy management in homes have been anticipated to become popular since deregulation of electric power retailing in April 2016. Due to the adoption of the Wi-SUN communications standard for smart meters by Japanese electric companies, the use of the Wi-SUN Alliance's Wi-SUN standard for the 920 MHz band for communications between 1) power meters and HEMS devices and 2) HEMS devices and HAN (Home Area Network) is expanding. HEMS devices have two communication control systems in order to control two series of communications functions. Conventionally, these have all been controlled individually by software. Renesas has developed a dual stack to control two networks using a single communications control system. This dual stack supports the aforementioned MAC stack and IP stack.

Dual Stack

 

Towards More Stable Communications

If the number of surrounding communication devices increases, the software processing load for discriminating addresses also increases. Renesas communication devices (RAA604S00 and RL78/G1H) have a built-in function for automatically discriminating two series of communication addresses. Thus, even if the number of surrounding communication devices increases, the two series of communication addresses can be discriminated confidently and without delay. As a result, the software processing load can be lightened, helping to avoid system instability stemming from erroneous reception or other problems.