diff --git a/apps/wsn-main/Makefile b/apps/wsn-main/Makefile
index 048b24d..8d59c4d 100644
--- a/apps/wsn-main/Makefile
+++ b/apps/wsn-main/Makefile
@@ -12,4 +12,6 @@ USEMODULE += bme280_i2c
 USEMODULE += wsn
 EXTERNAL_MODULE_DIRS += $(CURDIR)/../../sys/wsn
 
+CFLAGS += -DNODE_ID=\"$(NODE_ID)\"
+
 include $(RIOTBASE)/Makefile.include
diff --git a/apps/wsn-main/main.c b/apps/wsn-main/main.c
index 3d3fd55..ff95dae 100644
--- a/apps/wsn-main/main.c
+++ b/apps/wsn-main/main.c
@@ -24,6 +24,10 @@
     #define TICKS_PER_SEC US_PER_SEC
 #endif
 
+#ifndef NODE_ID
+    #define NODE_ID ""
+#endif
+
 #define SLEEP 5 // seconds
 
 
@@ -98,6 +102,18 @@ int main(void)
         nanocbor_fmt_uint(&enc, 0);
         nanocbor_fmt_uint(&enc, now / TICKS_PER_SEC);
 
+        // Serial number
+        nanocbor_fmt_uint(&enc, 1);
+        nanocbor_fmt_uint(&enc, cpuid);
+
+        // Name (Node Identifier)
+        nanocbor_fmt_uint(&enc, 2);
+        nanocbor_put_tstr(&enc, NODE_ID);
+
+        // Frame sequence number
+        nanocbor_fmt_uint(&enc, 3);
+        nanocbor_fmt_uint(&enc, loop);
+
         saul_reg_t *dev = saul_reg;
         while (dev) {
             // TODO Support 2 BME280 sensors at addresses 0x76 and 0x77
diff --git a/sys/include/wsn.h b/sys/include/wsn.h
index 030cdf1..9f94bb5 100644
--- a/sys/include/wsn.h
+++ b/sys/include/wsn.h
@@ -13,6 +13,11 @@
 #ifndef WSN_H
 #define WSN_H
 
+/**
+ * @brief Uniquely identifies the mote
+ */
+extern uint64_t cpuid;
+
 /**
  * @brief Code to run at boot
  *
diff --git a/sys/wsn/Makefile.dep b/sys/wsn/Makefile.dep
index 0cf4ed5..61a3cbc 100644
--- a/sys/wsn/Makefile.dep
+++ b/sys/wsn/Makefile.dep
@@ -1,3 +1,5 @@
+FEATURES_REQUIRED = periph_cpuid
+
 # Storage
 USEMODULE += fatfs_vfs
 USEMODULE += mtd_sdcard
diff --git a/sys/wsn/wsn.c b/sys/wsn/wsn.c
index fdd2fe4..039917b 100644
--- a/sys/wsn/wsn.c
+++ b/sys/wsn/wsn.c
@@ -2,14 +2,39 @@
 #include <log.h>
 #include <net/netif.h>
 #include <net/gnrc/netif.h>
+#include <periph/cpuid.h>
 
 // Project
 #include "settings.h"
 #include "wsn.h"
 
 
+uint64_t cpuid = 0;
+
+
 void wsn_boot(void)
 {
+    /*
+     * ID
+     *
+     * XXX In the cc2539 the CPU id is based on the MAC address, which is
+     * defined by two 32bit little-endian words stored in memory: first the
+     * most-significat word (IEEE_ADDR_MSWORD), then the less-significat word
+     * (IEEE_ADDR_MSWORD). But the CPU id is read from memory as-is.
+     *
+     * For example if in memory we have 00:4b:12:00 2e:15:40:19 then:
+     * - MAC address is 00:12:4B:00:19:40:15:2E
+     * - But CPU id is  00:4b:12:00:2e:15:40:19
+     *
+     */
+    uint8_t buffer[CPUID_LEN];
+    cpuid_get(buffer);
+
+    for (unsigned int i = 0; i < CPUID_LEN; i++) {
+        cpuid = cpuid << 8;
+        cpuid |= buffer[i];
+    }
+
     /*
      * Storage
      */