Also consider that a "channel" number with more than four digits will produce a match:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $text = shift;
 print qq{text '$text'};
 ;;
 my $match = my ($band, $channel) = $text =~ /Signal LTE-FDD (\d{1,2})
+; Channel (\d{3,4})/i;
 ;;
 if ($match) {
   print qq{band '$band'  channel '$channel'};
   }
 else {
   print 'no match';
   }
"  "Signal LTE-FDD 45; Channel 123456789"
text 'Signal LTE-FDD 45; Channel 123456789'
band '45'  channel '1234'
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You may want to use the  \A \z string beginning/end assertions or a  (?!\d) negative look-ahead to limit such matches. See Assertions and Look-Around Assertions in perlre.

Update: Note also that use of the  $& regex special variable or its "friends"  $` $' anywhere in a script imposes significant regex matching performance penalties everywhere in the script. See perlvar.