Nordic has show coffee machine using BLE IPV6. The BLE chip on coffee machine shall work as Master for IPV6 communication with internet? If so, does this chip drain much more power than that that BLE chip without IPV6? How much it would be? If it is too much it means that BLE chip with IPV6 function can only operate with power supply and can not work with battery only!
You can find information regarding the latest IoT SDK here, nRF51_IoT_SDK->doc
We have implemented node role according the Internet Protocol Support Profile(IPSP). The communication between the devices is done using IPv6 packets over the BLE transport. In this BLE transport our stack will be a slave when in a connection.
In the BLE transport Connection Oriented Channels with the Credit Based Flow Control Mode is utilized. With this the first packet typically has a 23 byte payload, while the consecutive packets typically have a 27 byte payload.
IPv6 requires the maximum transmission unit (MTU) to be at least 1280 bytes, and sending this amount over the BLE transport for every IPv6 packet would add a huge overhead compared to normal BLE. However, we have implemented 6LoWPAN which compresses UDP and IPv6 headers significantly, please see this draft from IETF for more information. Because of 6LoWPAN the IPv6 overhead is typically 6 bytes for link local addresses and typically 23 bytes for global addresses. This means that you can get away with sending one BLE packet if your payload is small enough.
So the power consumption increase of sending your payload over IPv6 over BLE compared to normal BLE shouldn't be too big. For normal BLE power profile examine the S110 SoftDevice specification, Chapter 14.
Other than that, we don't have power profiles for our IP stack. Remember that the IoT SDK still is experimental.
It can operate on a battery, for how long depends on the size of the battery, and the application.
Dear Peter
Thanks for your reply.
I noticed the demo on your coffee machine with BLE IPV6 has 3 type of devices: 1. coffee machine as you told me in your email is set as Slave. 2. Tags for different cups, are these also Slave? then which is master? 3.Raspberry PI as edge router. How this computer is connected with coffee machine? by UART, USB or BLE? If it is BLE that mean it shall be set as a Master to communite with devices 1 and 2 and transfer the data from them to cloud? Believed you connect Raspberry PI thru RJ45 LAN port to a normal router to internet. Can this be done by wifi too?
I have another question, BLE edge router, in realty, does it mean we need to develop standalone headless hub to bridge BLE network and internet. If yes that mean devices with BLE IPV6 ready still can not readily use current internet equipment for internet connection, and still need a kind of hub/router. It seems there is no any body providing this kind of router in the market now. What is your advice on how we should do with this edge router if we use your BLE IPV6 stack for our products?
Regards
Brandon
Coffee machine was connected to a nRF DK (ipv6 node) set up as slave, with RPi as master.
The cup tags were just regular beacons talking to another nRF DK set up as scanner. This scanner talked to the other DK (ipv6 node) using wires (SPI or UART)
The RPi was connected to the computer over LAN. This means that the computer, the RPi and the coffee machine node was on the same ipv6 LAN. The RPi could have been connected to the computer over wifi as well using a WLAN router, and be accessed from the internet through this router.
The other question:
Our example used a headless router (RPi) to bridge the BLE network with the LAN. This is just meant for development and is not a good solution if you want to make an ipv6 BLE product. For that, we have to wait for the router manufacturers to implement BLE support.
However, many projects using the bluetooth interface on OpenWRT routers have come up lately. The linux kernel used by these routers does now support BLE and 6LoWPAN. Search for OpenWRT in the blog section, devzone.nordicsemi.com/.../, for guides on how to set this up. And all you need is a supported device and a BLE dongle.
We have had great success implementing BLE and 6LoWPAN on these routers, and the IoT SDK examples now connect directly to the router, they get an ip, and you can ping them from the rest of the network (LAN, WLAN, WAN etc.)
Thanks Stian and Peter
