diff --git a/sys/net/sixlowpan/sixlowborder.h b/sys/net/sixlowpan/sixlowborder.h
index ada8333119..f2e790c7b7 100644
--- a/sys/net/sixlowpan/sixlowborder.h
+++ b/sys/net/sixlowpan/sixlowborder.h
@@ -12,7 +12,7 @@
 
 extern ipv6_addr_t abr_addr;
 
-uint16_t border_get_serial_reader();
+uint16_t border_get_serial_reader(void);
 
 uint8_t *get_serial_out_buffer(int offset);
 uint8_t *get_serial_in_buffer(int offset);
diff --git a/sys/net/sixlowpan/sixlowip.c b/sys/net/sixlowpan/sixlowip.c
index a0dd1e0d41..05470a7600 100644
--- a/sys/net/sixlowpan/sixlowip.c
+++ b/sys/net/sixlowpan/sixlowip.c
@@ -18,9 +18,7 @@ uint8_t buffer[BUFFER_SIZE];
 msg_t msg_queue[IP_PKT_RECV_BUF_SIZE];
 struct ipv6_hdr_t* ipv6_buf;
 struct icmpv6_hdr_t* icmp_buf;
-uint8_t ipv6_ext_hdr_len;
 uint8_t *nextheader;
-iface_t iface;
 uint8_t iface_addr_list_count = 0;
 int udp_packet_handler_pid = 0;
 int tcp_packet_handler_pid = 0;
diff --git a/sys/net/sixlowpan/sixlowmac.c b/sys/net/sixlowpan/sixlowmac.c
index e000f08695..da6206e043 100644
--- a/sys/net/sixlowpan/sixlowmac.c
+++ b/sys/net/sixlowpan/sixlowmac.c
@@ -18,15 +18,10 @@
 
 char radio_stack_buffer[RADIO_STACK_SIZE];
 msg_t msg_q[RADIO_RCV_BUF_SIZE];
-uint8_t snd_buffer[RADIO_SND_BUF_SIZE][PAYLOAD_SIZE];
 
 static uint8_t r_src_addr;
 uint8_t buf[PAYLOAD_SIZE];
-uint16_t packet_length;
 static uint8_t macdsn;
-//static uint8_t macbsn;
-
-mutex_t buf_mutex;
 
 static radio_packet_t p;
 static msg_t mesg;
diff --git a/sys/net/sixlowpan/sixlowmac.h b/sys/net/sixlowpan/sixlowmac.h
index f9b63e0d53..4cd4148455 100644
--- a/sys/net/sixlowpan/sixlowmac.h
+++ b/sys/net/sixlowpan/sixlowmac.h
@@ -11,7 +11,6 @@
 
 #define RADIO_STACK_SIZE            512
 #define RADIO_RCV_BUF_SIZE          64
-#define RADIO_SND_BUF_SIZE          100
 #define RADIO_SENDING_DELAY         1000
 
 extern uint16_t fragmentcounter;
diff --git a/sys/net/sixlowpan/sixlownd.c b/sys/net/sixlowpan/sixlownd.c
index ed5be56b00..dbafcf75be 100644
--- a/sys/net/sixlowpan/sixlownd.c
+++ b/sys/net/sixlowpan/sixlownd.c
@@ -17,7 +17,6 @@
 /* extern variables */
 uint8_t opt_hdr_len = 0;
 uint8_t ipv6_ext_hdr_len = 0;
-uint16_t packet_length;
 
 /* counter */
 uint8_t abr_count = 0;
@@ -26,9 +25,6 @@ uint8_t def_rtr_count = 0;
 uint8_t rtr_sol_count = 0;
 uint8_t prefix_count = 0;
 
-/* global interface*/
-iface_t iface;
-
 /* datastructures */
 abr_cache_t abr_cache[ABR_CACHE_SIZE];
 nbr_cache_t nbr_cache[NBR_CACHE_SIZE];
diff --git a/sys/net/sixlowpan/sixlowpan.c b/sys/net/sixlowpan/sixlowpan.c
index c7919cb49e..a655481283 100644
--- a/sys/net/sixlowpan/sixlowpan.c
+++ b/sys/net/sixlowpan/sixlowpan.c
@@ -8,8 +8,6 @@
 #include <thread.h>
 #include <mutex.h>
 #include <hwtimer.h>
-#include <rtc.h>
-//#include <lpc2387-rtc.h>
 #include "msg.h"
 #include "sixlowmac.h"
 #include "sixlowpan.h"
@@ -30,7 +28,7 @@ uint8_t max_frag_initial = 0;
 uint8_t position;
 uint8_t max_frag;
 
-struct ipv6_hdr_t *ipv6_buf;
+static struct ipv6_hdr_t *ipv6_buf;
 
 /* length of compressed packet */
 uint16_t comp_len;
@@ -1397,9 +1395,6 @@ void sixlowpan_init(transceiver_type_t trans, uint8_t r_addr, int as_border){
     /* init mac-layer and radio transceiver */
     sixlowmac_init(trans);
 
-    rtc_init();
-    rtc_enable();
-
     /* init interface addresses */
     memset(&iface,0,sizeof(iface_t));
     set_radio_address(r_addr);