📄 g1-1-2.htm
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lang=EN-US>TACS</SPAN></FONT></P></TD>
<TD
style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 68.95pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt"
vAlign=top width=92>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>450</SPAN></FONT></P>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>900</SPAN></FONT></P></TD>
<TD
style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 70.85pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt"
vAlign=top width=94>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>1984</SPAN></FONT></P>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>1990</SPAN></FONT></P></TD>
<TD
style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 70.9pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt"
vAlign=top width=95>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>60</SPAN></FONT></P>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>60</SPAN></FONT></P></TD></TR>
<TR>
<TD
style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 70.05pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt"
vAlign=top width=93>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
style="mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman">西班牙</SPAN></FONT></P></TD>
<TD
style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 75pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt"
vAlign=top width=100>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>NMT</SPAN></FONT></P>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>TACS</SPAN></FONT></P></TD>
<TD
style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 68.95pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt"
vAlign=top width=92>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>450</SPAN></FONT></P>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>900</SPAN></FONT></P></TD>
<TD
style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 70.85pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt"
vAlign=top width=94>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>1982</SPAN></FONT></P>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>1990</SPAN></FONT></P></TD>
<TD
style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 70.9pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt"
vAlign=top width=95>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>60</SPAN></FONT></P>
<P class=MsoNormal
style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-ALIGN: center"
align=center><FONT face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>60</SPAN></FONT></P></TD></TR></TBODY></TABLE>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; TEXT-INDENT: 21pt; TEXT-ALIGN: justify; mso-char-indent-count: 2.0; mso-char-indent-size: 10.5pt"><SPAN
style="mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman"><FONT
face=楷体_GB2312
color=#000066>蜂窝移动通信的出现可以说是移动通信的一次革命。其频率复用大大提高了频率利用率并增大系统容量，网络的智能化实现了越区转接和漫游功能，扩大了客户的服务范围，但上述模拟系统有四大缺点：</FONT></SPAN></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; MARGIN-LEFT: 43pt; TEXT-INDENT: -18pt; TEXT-ALIGN: justify; mso-list: l2 level1 lfo4; tab-stops: list 43.0pt"><FONT
face=楷体_GB2312 color=#000066><SPAN lang=EN-US>1.<SPAN
style="FONT-WEIGHT: normal; FONT-SIZE: 7pt; FONT-STYLE: normal; FONT-VARIANT: normal">
</SPAN></SPAN><SPAN
style="mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman">各系统间没有公共接口；</SPAN></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; MARGIN-LEFT: 43pt; TEXT-INDENT: -18pt; TEXT-ALIGN: justify; mso-list: l2 level1 lfo4; tab-stops: list 43.0pt"><FONT
face=楷体_GB2312 color=#000066><SPAN lang=EN-US>2.<SPAN
style="FONT-WEIGHT: normal; FONT-SIZE: 7pt; FONT-STYLE: normal; FONT-VARIANT: normal">
</SPAN></SPAN><SPAN
style="mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman">很难开展数据承载业务；</SPAN></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; MARGIN-LEFT: 43pt; TEXT-INDENT: -18pt; TEXT-ALIGN: justify; mso-list: l2 level1 lfo4; tab-stops: list 43.0pt"><FONT
face=楷体_GB2312 color=#000066><SPAN lang=EN-US>3.<SPAN
style="FONT-WEIGHT: normal; FONT-SIZE: 7pt; FONT-STYLE: normal; FONT-VARIANT: normal">
</SPAN></SPAN><SPAN
style="mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman">频谱利用率低无法适应大容量的需求；</SPAN></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; MARGIN-LEFT: 43pt; TEXT-INDENT: -18pt; TEXT-ALIGN: justify; mso-list: l2 level1 lfo4; tab-stops: list 43.0pt"><FONT
face=楷体_GB2312 color=#000066><SPAN lang=EN-US>4.<SPAN
style="FONT-WEIGHT: normal; FONT-SIZE: 7pt; FONT-STYLE: normal; FONT-VARIANT: normal">
</SPAN></SPAN><SPAN
style="mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman">安全保密性差，易被窃听，易做“假机”。</SPAN></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; MARGIN-LEFT: 25pt; TEXT-ALIGN: justify"><FONT
color=#000066><SPAN
style="mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman"><FONT
face=楷体_GB2312>尤其是在欧洲系统间没有公共接口相互之间不能漫游，对客户之间造成很大的不便。</FONT></SPAN><FONT
face=楷体_GB2312><SPAN lang=EN-US><O:P>
</O:P></SPAN></FONT></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; TEXT-INDENT: 30.25pt; TEXT-ALIGN: justify; mso-char-indent-count: 2.88; mso-char-indent-size: 10.5pt"><FONT
face=楷体_GB2312 color=#000066><SPAN lang=EN-US><SPAN
style="mso-spacerun: yes"> </SPAN>GSM数字移动通信系统史源于欧洲。早在1982年，欧洲已有几大模拟蜂窝移动系统在运营，例如北欧多国的NMT（北欧移动电话）和英国的TACS（全接入通信系统），西欧其它各国也提供移动业务。当时这些系统是国内系统，不可能在国外使用。为了方便全欧洲统一使用移动电话，需要一种公共的系统，1982年北欧国家向CEPT（欧洲邮电行政大）提交了一份建议书，要求制定900MHz频段的公共欧洲电信业务规范。在这次大会上就成立了一个在欧洲电信标准学会（ETSI）技术委员会下的“移动特别小组＼Group<SPAN
style="mso-spacerun: yes">
</SPAN>SpecialMobile）简称“GSM”，来制定有关的标准和建议书。<O:P>
</O:P></SPAN></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; TEXT-ALIGN: justify"><FONT
face=楷体_GB2312 color=#000066><SPAN lang=EN-US><SPAN
style="mso-spacerun: yes">
</SPAN>1986年在巴黎，该小组对欧洲各国及各公司经大量研究和实验后所提出的8个建议系统进行了现场实验。<O:P>
</O:P></SPAN></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; TEXT-ALIGN: justify"><FONT
face=楷体_GB2312 color=#000066><SPAN lang=EN-US><SPAN
style="mso-spacerun: yes">
</SPAN>1987年5月GSM成员国就数字系统采用窄带时分多址TDMA、规则脉冲激励线性预测RPE一LTP话音编码和高斯滤波最小移频键控GMSK调制方式达成一致意见。同年，欧洲17个国家的运营者和管理者签署了谅解备忘录（MoU），相互达成履行规范的协议。与此同时还成立了MoU组织，致力于GSM标准的发展。<O:P>
</O:P></SPAN></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; TEXT-ALIGN: justify"><FONT
face=楷体_GB2312 color=#000066><SPAN
lang=EN-US>1990年完成了GSM900的规范，共产生大约130项的全面建议书，不同建议书经分组而成为一套12系列。<O:P>
</O:P></SPAN></FONT></P>
<P class=MsoNormal
style="TEXT-JUSTIFY: inter-ideograph; TEXT-ALIGN: justify"><FONT
face=楷体_GB2312 color=#000066><SPAN lang=EN-US><SPAN
style="mso-spacerun: yes">
</SPAN>1991年在欧洲开通了第一个系统，同时MoU组织为该系统设计和注册了市场商标，将GSM更名为“全球移动通信系统”（Globa1
system for<SPAN style="mso-spacerun: yes"> </SPAN>Mobile<SPAN
style="mso-spacerun: yes">
</SPAN>communications）。从此移动通信跨入了第二代数字移动通信系统。同年，移动特别小组还完成了制定1800MHz频段的公共欧洲电信业务的规范，名为DCSI800系统。该系统与<SPAN
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