While composing an SMS , increase length of 2nd sms from 146 to 150 chars?

When i compose a long SMS (of length 3 smses each of 160 , 146 , 153 chars) it gets divided into chars of 151 , 153 & 153 before being sent .

Also 7 chars at the end shift to 2nd sms . Can anyone explain me the reason for the same ?

Also can i change the limit of 开发者_JS百科compose message for 2nd sms from 146 to 150 chars ? (I guess its the requirement for CDMA . 146 is for GSM)

Large SMS can be sent using multipart SMS, in which case each message will start with a user data header UDH containing segmentation information. Since UDH is part of the payload, the number of available characters per segment will be only 153.