diff --git a/platform/esb/dev/tr1001-gcr.c b/platform/esb/dev/tr1001-gcr.c
index 5c73e00f1..a65a16f4e 100644
--- a/platform/esb/dev/tr1001-gcr.c
+++ b/platform/esb/dev/tr1001-gcr.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: tr1001-gcr.c,v 1.3 2006/10/09 11:56:13 adamdunkels Exp $
+ * @(#)$Id: tr1001-gcr.c,v 1.4 2006/10/09 21:05:37 nifi Exp $
  */
 /**
  * \addtogroup esb
@@ -94,6 +94,8 @@ static unsigned short tr1001_rxlen = 0;
  */
 volatile unsigned char tr1001_rxstate = RXSTATE_READY;
 
+static u8_t radio_active;
+
 static u16_t rxcrc, rxcrctmp;
 
 /*
@@ -612,6 +614,8 @@ tr1001_send(u8_t *packet, u16_t len)
   /* Prepare the transmission. */
   prepare_transmission(NUM_SYNCHBYTES);
 
+  radio_active = 1;
+
   crc16 = 0xffff;
 
   gcr_init();
@@ -764,5 +768,17 @@ tr1001_sstrength_value(unsigned int type)
 }
 #endif /* TR1001_STATISTICS */
 /*---------------------------------------------------------------------------*/
+unsigned char
+tr1001_active(void)
+{
+  return radio_active;
+}
+/*--------------------------------------------------------------------------*/
+void
+tr1001_clear_active(void)
+{
+  radio_active = 0;
+}
+/*--------------------------------------------------------------------------*/
 /** @} */
 /** @} */
diff --git a/platform/esb/dev/tr1001.h b/platform/esb/dev/tr1001.h
index 8106a9ae8..fe2b21c35 100644
--- a/platform/esb/dev/tr1001.h
+++ b/platform/esb/dev/tr1001.h
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: tr1001.h,v 1.2 2006/10/09 11:56:13 adamdunkels Exp $
+ * @(#)$Id: tr1001.h,v 1.3 2006/10/09 21:05:37 nifi Exp $
  */
 #ifndef __TR1001_H__
 #define __TR1001_H__
@@ -149,6 +149,8 @@ unsigned short tr1001_packets_ok(void);
 unsigned short tr1001_packets_dropped(void);
 void tr1001_clear_packets(void);
 unsigned short tr1001_sstrength_value(unsigned int type);
+unsigned char tr1001_active(void);
+void tr1001_clear_active(void);
 #endif /* TR1001_STATISTICS */
 
 #endif /* __TR1001_H__ */