EARLIDS

      Eyelids  are  useful  organs,          modulation   scheme   discriminates
and earlids  that would  enable one          well   against  weak   signals.   A
to shut out sound voluntarily would          computer keeps track of what cell a
also be useful.  However, if we put          subscriber is in or finds  him when
our  technological  imagination  to          he is  called and also  assigns him
work,  we can  do much  better than          an unused  channel.  We  propose to
that.                                        extend    this   to    a   personal
                                             radiotelephone   which    will   be
      Suppose all sound  reaching a          feasible  when  electronics  is yet
person's   auditory   nerve   comes          more compact.
through an electronic channel.  The
source of the sound is selected and                The individual telephone will
the  sound  may  be  filtered.  The          have  a  number  of  social effects
following  are possible  sources of          some of  which might be  bad unless
sound:                                       compensated by suitable  customs or
                                             laws.  Any  person will be  able to
      1.  The  ambient  sound.   It          reach                               any
                                                                                 other
                                                                                 person
                                                                                 at
                                                                                 any
                                                                                 time.
comes from microphones  attached to          This  can  allow  people   who  are
the person  and may be  filtered by          physically  separated instantaneous
frequency to eliminate band limited          communication   while    they   are
noises.   It  may  be   limited  to          engaged in other  activities.  This
eliminate loud  noises.  It  may be          will  enable  separated  people  to
selected  directionally   to  allow          maintain    much    closer   social
conversation at a distance.                  relationships  of  a   personal  or
                                             family  or  professional  or  hobby
      2. Radio.                              character.   It  obviously requires
                                             an   elaborate   system   for   the
      3.   A  source   of  recorded          protection of privacy from unwanted
sound.                                       calls.   One  must be  able  to (1)
                                             reject  calls from  certain people,
      4. The  individual telephone.          (2)  accept   calls  only   from  a
The  idea  here  is  that telephone          certain class of people,  (3) allow
numbers  should  be  attachable  to          urgent                              communication,
                                                                                 etc.
                                                                                  Perhaps
persons  as  well  as   to  places.          if a  call is declared  urgent, the
Systems  of  cellular  mobile radio          sender  incurs  a  charge   on  his
telephones  have been  proposed for          telephone  bill  if  the  recipient
the    usual    mobile    telephone          doesn't  agree  that  the  call was
applications.   In  fact,  AT&T has          urgent.
applied   for  frequencies   for  a
system  that  will   allow  500,000
mobile  radiotelephones in  a city.
In this system, the city is divided
into  cells,  and  the  frequencies
assigned to  a cell may  be re-used
in distant cells.   Presumably, the


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