diff --git a/README.md b/README.md
index cae7d0d..f8b1982 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
-LoRa Time on Air calculator
-===========================
+LoRa/LoRaWAN Time on Air calculator
+===================================
 
-A calculator of the time on air of LoRa PHY frame in Python.
+A calculator of the time on air (ToA) of LoRa/LoRaWAN PHY frame in Python.
 
 This script refers to the section 4.1.1.6. LoRa Packet Structure,
 [SX1276/77/78/79 Datasheet rev.5][http://www.semtech.com/images/datasheet/sx1276.pdf].
@@ -34,32 +34,34 @@ the --downlink option should be specified.
 
 ## Usage
 
-    lorawan_toa.py [-h] [--band-width N_BW] [--disable-auto-ldro]
-                        [--enable-ldro] [--disable-eh] [--downlink]
-                        [--disable-crc] [--cr N_CR] [--preamble N_PREAMBLE] [-v]
-                        [-d]
-                        SF SIZE
+    lorawan_toa.py [-h] [--band-width NUMBER] [--disable-auto-ldro]
+                   [--enable-ldro] [--disable-eh] [--downlink]
+                   [--disable-crc] [--cr NUMBER] [--preamble NUMBER]
+                   [--duty-cycle NUMBER] [-v] [-d]
+                   SF SIZE
+    
+    LoRa Time on Air calculator.
     
     positional arguments:
-      SF                    Spreading Factor. It should be from 7 to 12.
-      SIZE                  PHY payload size in byte. It's equal to the MAC
-                            payload + 5.
+      SF                   Spreading Factor. It should be from 7 to 12.
+      SIZE                 PHY payload size in byte. It's equal to the MAC payload
+                           + 5.
     
     optional arguments:
-      -h, --help            show this help message and exit
-      --band-width N_BW     bandwidth in kHz. default is 125 kHz.
-      --disable-auto-ldro   disable the auto LDRO and disable LDRO.
-      --enable-ldro         This option is available when the auto LDRO is
-                            disabled.
-      --disable-eh          disable the explicit header.
-      --downlink            disable the CRC field, which is for the LoRaWAN
-                            downlink stream.
-      --disable-crc         same effect as the --downlink option.
-      --cr N_CR             specify the CR value. default is 1 as LoRaWAN does.
-      --preamble N_PREAMBLE
-                            specify the preamble. default is 8 for AS923.
-      -v                    enable verbose mode.
-      -d                    increase debug mode.
+      -h, --help           show this help message and exit
+      --band-width NUMBER  bandwidth in kHz. default is 125 kHz.
+      --disable-auto-ldro  disable the auto LDRO and disable LDRO.
+      --enable-ldro        This option is available when the auto LDRO is
+                           disabled.
+      --disable-eh         disable the explicit header.
+      --downlink           disable the CRC field, which is for the LoRaWAN
+                           downlink stream.
+      --disable-crc        same effect as the --downlink option.
+      --cr NUMBER          specify the CR value. default is 1 as LoRaWAN does.
+      --preamble NUMBER    specify the preamble. default is 8 for AS923.
+      --duty-cycle NUMBER  specify the duty cycle in percentage. default is 1 %.
+      -v                   enable verbose mode.
+      -d                   increase debug mode.
 
 ## Examples
 
@@ -68,20 +70,23 @@ below example, it show detail information in SF 12, 64 bytes of PHY payload,
 125 kHz bandwidth, preamble 8.
 
     % python lorawan_toa.py 12 64 -v
-    PHY payload size    : 64 Bytes
-    MAC payload size    : 59 Bytes
-    Spreading Factor    : 12
+    PHY payload size    : 16 Bytes
+    MAC payload size    : 11 Bytes
+    Spreading Factor    : 7
     Band width          : 125 kHz
-    Low data rate opt.  : enable
+    Low data rate opt.  : disable
     Explicit header     : enable
     CR (coding rate)    : 1 (4/5)
-    Symbol Rate         : 30.518 symbol/s
-    Symbol Time         : 32.768 msec/symbol
+    Symbol Rate         : 976.562 symbol/s
+    Symbol Time         : 1.024 msec/symbol
     Preamble size       : 8 symbols
-    Packet symbol size  : 73 symbols
-    Preamble ToA        : 401.408 msec
-    Payload ToA         : 2392.064 msec
-    Time on Air         : 2793.472 msec
+    Packet symbol size  : 38 symbols
+    Preamble ToA        : 12.544 msec
+    Payload ToA         : 38.912 msec
+    Time on Air         : 51.456 msec
+    Duty Cycle          : 1 %
+    Min span of a cycle : 5 sec
+    Max Frames per day  : 16791 frames
 
 without the -v option, it simply shows the ToA.