Changing and running Different MAC Protocols in Cooja Contiki OS

The network stack in Contiki OS is a little different compared to the traditional TCP/IP network stack. In place of MAC Layer, we have three layers namely Framer, Radio Duty-Cycle (RDC) and Medium Access Control (MAC). The different layers can be changed by accessing the global variables NETSTACK_FRAMER, NETSTACK_RDC and NETSTACK_MAC. These variables can be found in core/net/netstack.h

By default, the following configuration is used in Contiki OS:-

1. Network: rime_driver
2. MAC: nullmac_driver
3. RDC: nullrdc_driver
4. Framer: framer_nullmac
5. Radio: nullradio_driver

A detailed explanation about the network stack can be found in Contiki Wiki. Let us now dive into the tutorial.

Note: We will be using the project configuration file method as it is a much better approach and doesn’t hamper with the main platform configuration files.

Step 1: Navigate to home/contiki-2.7/examples/ipv6

Step 2: Make a copy of backup file of Makefile and name it Makefile-copy

Step 3: Let’s create a file called my-conf.h. This file should be inserted into your Makefile. Open the file named Makefile using any editor like gedit, nano or vi.

CONTIKI = ../../..
CFLAGS += -DPROJECT_CONF_H=\"my-conf.h\" 

Step 4: Now open your file my-conf.h using any editor and start editing based on your required configuration

#ifndef NETSTACK_CONF_MAC
#define NETSTACK_CONF_MAC     csma_driver
#endif /* NETSTACK_CONF_MAC */
#ifndef NETSTACK_CONF_RDC
#define NETSTACK_CONF_RDC     contikimac_driver
#endif /* NETSTACK_CONF_RDC */
#ifndef NETSTACK_CONF_RDC_CHANNEL_CHECK_RATE
#define NETSTACK_CONF_RDC_CHANNEL_CHECK_RATE 8
#endif /* NETSTACK_CONF_RDC_CHANNEL_CHECK_RATE */
#ifndef NETSTACK_CONF_RADIO
#define NETSTACK_CONF_RADIO   cc2420_driver
#endif /* NETSTACK_CONF_RADIO */
#ifndef NETSTACK_CONF_FRAMER
#define NETSTACK_CONF_FRAMER  framer_802154
#endif /* NETSTACK_CONF_FRAMER */

Step 5: In order for your configuration to work you need to navigate to the folder /home/contiki-2.7/platform/sky/contiki-conf.h

Step 6: Open contiki-conf.h and bring the following lines at the start of the file below define CONTIKI_CONF_H which is located at the end of contiki-conf.h

 /* include the project config / / PROJECT_CONF_H might be defined in the project Makefile */
 ifdef PROJECT_CONF_H
 include PROJECT_CONF_H
 endif /* PROJECT_CONF_H */

Note 1: Your contiki-conf.h file beginning lines should look like this after making the changes

/* -- C -- */ ifndef CONTIKI_CONF_H
 define CONTIKI_CONF_H

 /* include the project config / / PROJECT_CONF_H might be defined in the project Makefile */ ifdef PROJECT_CONF_H
 include PROJECT_CONF_H
 endif /* PROJECT_CONF_H */

Note 2: The entire contiki-conf.h file looks like this after modifications

/* -- C -- */ ifndef CONTIKI_CONF_H
 define CONTIKI_CONF_H
 /* include the project config / / PROJECT_CONF_H might be defined in the project Makefile */ ifdef PROJECT_CONF_H
 include PROJECT_CONF_H
 endif /* PROJECT_CONF_H */ ifdef PLATFORM_CONF_H
 include PLATFORM_CONF_H
 else
 include "platform-conf.h"
 endif /* PLATFORM_CONF_H */ ifndef NETSTACK_CONF_MAC
 define NETSTACK_CONF_MAC     csma_driver
 endif /* NETSTACK_CONF_MAC */ ifndef NETSTACK_CONF_RDC
 define NETSTACK_CONF_RDC     contikimac_driver
 endif /* NETSTACK_CONF_RDC */ ifndef NETSTACK_CONF_RDC_CHANNEL_CHECK_RATE
 define NETSTACK_CONF_RDC_CHANNEL_CHECK_RATE 8
 endif /* NETSTACK_CONF_RDC_CHANNEL_CHECK_RATE */ ifndef NETSTACK_CONF_RADIO
 define NETSTACK_CONF_RADIO   cc2420_driver
 endif /* NETSTACK_CONF_RADIO */ ifndef NETSTACK_CONF_FRAMER
 define NETSTACK_CONF_FRAMER  framer_802154
 endif /* NETSTACK_CONF_FRAMER */ ifndef CC2420_CONF_AUTOACK
 define CC2420_CONF_AUTOACK              1
 endif /* CC2420_CONF_AUTOACK */ /* Specify whether the RDC layer should enable
    per-packet power profiling. */ define CONTIKIMAC_CONF_COMPOWER         1
 define XMAC_CONF_COMPOWER               1
 define CXMAC_CONF_COMPOWER              1
 if WITH_UIP6
 /* Network setup for IPv6 */ define NETSTACK_CONF_NETWORK sicslowpan_driver
 /* Specify a minimum packet size for 6lowpan compression to be
    enabled. This is needed for ContikiMAC, which needs packets to be
    larger than a specified size, if no ContikiMAC header should be
    used. */ define SICSLOWPAN_CONF_COMPRESSION_THRESHOLD 63
 define CONTIKIMAC_CONF_WITH_CONTIKIMAC_HEADER 0
 define CXMAC_CONF_ANNOUNCEMENTS         0
 define XMAC_CONF_ANNOUNCEMENTS          0
 ifndef QUEUEBUF_CONF_NUM
 define QUEUEBUF_CONF_NUM                8
 endif
 else /* WITH_UIP6 */ /* Network setup for non-IPv6 (rime). */ define NETSTACK_CONF_NETWORK rime_driver
 define COLLECT_CONF_ANNOUNCEMENTS       1
 define CXMAC_CONF_ANNOUNCEMENTS         0
 define XMAC_CONF_ANNOUNCEMENTS          0
 define CONTIKIMAC_CONF_ANNOUNCEMENTS    0
 ifndef COLLECT_NEIGHBOR_CONF_MAX_COLLECT_NEIGHBORS
 define COLLECT_NEIGHBOR_CONF_MAX_COLLECT_NEIGHBORS     32
 endif /* COLLECT_NEIGHBOR_CONF_MAX_COLLECT_NEIGHBORS */ ifndef QUEUEBUF_CONF_NUM
 define QUEUEBUF_CONF_NUM                16
 endif /* QUEUEBUF_CONF_NUM */ ifndef TIMESYNCH_CONF_ENABLED
 define TIMESYNCH_CONF_ENABLED           0
 endif /* TIMESYNCH_CONF_ENABLED */ if TIMESYNCH_CONF_ENABLED
 /* CC2420 SDF timestamps must be on if timesynch is enabled. */ undef CC2420_CONF_SFD_TIMESTAMPS
 define CC2420_CONF_SFD_TIMESTAMPS       1
 endif /* TIMESYNCH_CONF_ENABLED */ endif /* WITH_UIP6 */ define PACKETBUF_CONF_ATTRS_INLINE 1
 ifndef RF_CHANNEL
 define RF_CHANNEL              26
 endif /* RF_CHANNEL */ define CONTIKIMAC_CONF_BROADCAST_RATE_LIMIT 0
 define IEEE802154_CONF_PANID       0xABCD
 define SHELL_VARS_CONF_RAM_BEGIN 0x1100
 define SHELL_VARS_CONF_RAM_END 0x2000
 define PROFILE_CONF_ON 0
 ifndef ENERGEST_CONF_ON
 define ENERGEST_CONF_ON 1
 endif /* ENERGEST_CONF_ON */ define ELFLOADER_CONF_TEXT_IN_ROM 0
 ifndef ELFLOADER_CONF_DATAMEMORY_SIZE
 define ELFLOADER_CONF_DATAMEMORY_SIZE 0x400
 endif /* ELFLOADER_CONF_DATAMEMORY_SIZE */ ifndef ELFLOADER_CONF_TEXTMEMORY_SIZE
 define ELFLOADER_CONF_TEXTMEMORY_SIZE 0x800
 endif /* ELFLOADER_CONF_TEXTMEMORY_SIZE */ define AODV_COMPLIANCE
 define AODV_NUM_RT_ENTRIES 32
 define WITH_ASCII 1
 define PROCESS_CONF_NUMEVENTS 8
 define PROCESS_CONF_STATS 1
 /#define PROCESS_CONF_FASTPOLL    4/
 ifdef WITH_UIP6
 define RIMEADDR_CONF_SIZE              8
 define UIP_CONF_LL_802154              1
 define UIP_CONF_LLH_LEN                0
 define UIP_CONF_ROUTER                 1
 ifndef UIP_CONF_IPV6_RPL
 define UIP_CONF_IPV6_RPL               1
 endif /* UIP_CONF_IPV6_RPL */ /* configure number of neighbors and routes */ ifndef NBR_TABLE_CONF_MAX_NEIGHBORS
 define NBR_TABLE_CONF_MAX_NEIGHBORS     20
 endif /* NBR_TABLE_CONF_MAX_NEIGHBORS */ ifndef UIP_CONF_MAX_ROUTES
 define UIP_CONF_MAX_ROUTES   20
 endif /* UIP_CONF_MAX_ROUTES */ define UIP_CONF_ND6_SEND_RA        0
 define UIP_CONF_ND6_REACHABLE_TIME     600000
 define UIP_CONF_ND6_RETRANS_TIMER      10000
 define UIP_CONF_IPV6                   1
 ifndef UIP_CONF_IPV6_QUEUE_PKT
 define UIP_CONF_IPV6_QUEUE_PKT         0
 endif /* UIP_CONF_IPV6_QUEUE_PKT */ define UIP_CONF_IPV6_CHECKS            1
 define UIP_CONF_IPV6_REASSEMBLY        0
 define UIP_CONF_NETIF_MAX_ADDRESSES    3
 define UIP_CONF_ND6_MAX_PREFIXES       3
 define UIP_CONF_ND6_MAX_DEFROUTERS     2
 define UIP_CONF_IP_FORWARD             0
 ifndef UIP_CONF_BUFFER_SIZE
 define UIP_CONF_BUFFER_SIZE        240
 endif
 define SICSLOWPAN_CONF_COMPRESSION_IPV6        0
 define SICSLOWPAN_CONF_COMPRESSION_HC1         1
 define SICSLOWPAN_CONF_COMPRESSION_HC01        2
 define SICSLOWPAN_CONF_COMPRESSION             SICSLOWPAN_COMPRESSION_HC06
 ifndef SICSLOWPAN_CONF_FRAG
 define SICSLOWPAN_CONF_FRAG                    1
 define SICSLOWPAN_CONF_MAXAGE                  8
 endif /* SICSLOWPAN_CONF_FRAG */ define SICSLOWPAN_CONF_CONVENTIONAL_MAC    1
 define SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS       2
 ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
 define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS   5
 endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */ else /* WITH_UIP6 */ define UIP_CONF_IP_FORWARD      1
 define UIP_CONF_BUFFER_SIZE     108
 endif /* WITH_UIP6 */ define UIP_CONF_ICMP_DEST_UNREACH 1
 define UIP_CONF_DHCP_LIGHT
 define UIP_CONF_LLH_LEN         0
 ifndef  UIP_CONF_RECEIVE_WINDOW
 define UIP_CONF_RECEIVE_WINDOW  48
 endif
 ifndef  UIP_CONF_TCP_MSS
 define UIP_CONF_TCP_MSS         48
 endif
 define UIP_CONF_MAX_CONNECTIONS 4
 define UIP_CONF_MAX_LISTENPORTS 8
 define UIP_CONF_UDP_CONNS       12
 define UIP_CONF_FWCACHE_SIZE    30
 define UIP_CONF_BROADCAST       1
 define UIP_ARCH_IPCHKSUM        1
 define UIP_CONF_UDP             1
 define UIP_CONF_UDP_CHECKSUMS   1
 define UIP_CONF_PINGADDRCONF    0
 define UIP_CONF_LOGGING         0
 define UIP_CONF_TCP_SPLIT       0
 endif /* CONTIKI_CONF_H */

Testing the MAC Protocol changes

Fire up your Cooja simulator and run a TMote sky device. Confused?? Don’t worry! Follow this Cooja Hello World Tutorial to get started on Cooja simulations immediately. Check device configurations in Mote Output Tool discussed in Cooja Tools.