Sreekanth, P. V. <br/><br/>
Digital transmission hierarchies and networks  PDH,SDH and OTH / 

 - Hyderabad :  Universities Press ,  2010. 
 - Ppxxviii+532 
<br/><br/><label>ISBN: </label>97881 
<br/><br/><label>Subjects--Index Terms: </label>Data Communication,networking