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IS-95
���ҵðҹ�ͧ mobile ��� base station
����Ѻ dual-mode wideband spread spectrum �ҵðҹ��������ҹ㹻��������ԡҡѺ
800 MHz cellular bands ����ҴѴ�ŧ����Ѻ Personal communications
service(PCS) 1900 MHz �ҵðҹ����ʹ��º���ѷ Qualcomm ������Ѻ����������ͨҡ
AT&T , Motorola ���˹��§ҹ��蹷������Ǣ�ͧ IS-95 �� direct-sequence
CDMA ����������Ф����� pseudorandom code �����������ѹ �� 1988,The
Cellular Telecommunications Industry Association (CTIA) ��˹� User's
Performance Requirements (UPR) ����Ѻ cellular carrier's ��к� cellular
�ؤ���� ��� IS-95 ����ö�ͺʹͧ��͢�͡�˹���ҧ��� ��͡�˹���ҧ�����ҹ������
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Ease of transition and compatibility with existing analog system
Early availability and reasonable costs for dual-mode radios and
cells
Substantial capacity increase over analog system capacity
Privacy
Long life
adequate growth of second-generation technology
Quality
improvements (voice quality,service quality in terms of dropped
calls,constant voice quality level,etc.)
Ability
to introduce new features easily
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㹡����ҹ��͡�˹�����Ӥѭ�ҡ��з����
CDMA�繷������Ѻ�����դ����״����㹡���� �ҹ�٧��� Dual-mode operation
�������ö�������� CDMA channel 㹪�ǧ�������ͧ AMPS ����ͼ�����Դ����ͧ
����ͧ�١���¨��� CDMA control channel ����͡������������������ CDMA
protocol �������͡���� AMPS control channel ���������������к� AMPS
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