sim800 模式切換

SIM：訂戶標識模塊或訂戶標識模塊 (SIM: Subscriber Identity Module or Subscriber Identification Module)

SIM is an abbreviation of a Subscriber Identity Module or Subscriber Identification Module. SIM is a portable chip and an integrated circuit that firmly, stably and securely stores the international mobile subscriber identity (IMSI). It is a smart memory card that creates a possibility to make a phone call across the world where the availability of the user's network is stable.

SIM是訂戶身份模塊或訂戶身份模塊的縮寫 。 SIM是一種便攜式芯片和一種集成電路，可以牢固，穩定且安全地存儲國際移動用戶身份(IMSI)。 它是一種智能存儲卡，可以在穩定用戶網絡可用性的世界范圍內撥打電話。

SIM is commonly used in smartphones that function and manage on the GSM network. It is movable and a user can use it with any supporting smartphone.

SIM通常用于在GSM網絡上運行和管理的智能手機中。 它是可移動的，用戶可以在任何支持的智能手機上使用它。

SIM卡存儲什么信息？ (What information does a SIM card store?)

The SIM card carries essential information back and forth to the user's network and it also carries some of his personal and private data.

SIM卡可將重要信息往返于用戶的網絡，也可以攜帶其一些個人和私人數據。

• Phone number

  電話號碼

• Address book

  地址簿

• Network authorization data

  網絡授權數據

• Text messages

  短信

• Personal security keys

  個人安全密鑰

• Other data

  其他資料

A SIM also carries its,

SIM卡還帶有

• Unique serial number (ICCID)

  唯一序列號(ICCID)

• International Mobile Subscriber Identity (IMSI)

  國際移動訂戶身份(IMSI)

• Security information

  安全資訊

• Ciphering information

  加密信息

• And, temporary information associated to the local network, etc.

  并且，與局域網相關的臨時信息等。

SIM卡尺寸 (SIM Size)

The SIM size was nearly the size of a credit card when it was first developed. But the SIM quality size which discovered later carries a size of 15mm by 12mm. Now these days, micro and nano-SIM cards are used in some smartphones which are distinct in sizes.

SIM卡的大小幾乎是剛開發時的信用卡大小。 但是后來發現的SIM質量尺寸為15mm x 12mm。 如今，微型和納米SIM卡已在尺寸不同的某些智能手機中使用。

歷史 (History)

In 1991, the first SIM card was developed by Munich smart-card maker Giesecke and Devrient. The SIM, in the beginning, was identified and stated by the European Telecommunication Standards Institute.

1991年，慕尼黑智能卡制造商Giesecke和Devrient開發了第一張SIM卡。 最初，SIM卡是由歐洲電信標準協會識別并聲明的。

GSM與CDMA的區別 (Difference between GSM and CDMA)

GSM	CDMA
GSM is particularly for SIM.	CDMA is particularly for headset or phone.
GSM stands for Global System for Mobile communication.	CDMA stands for Code Division Multiple Access.
Technology supported FDMA and TDMA.	Technology supported CDMA.
The GSM is fundamentally based on wedge spectrum called a carrier.	The CDMA is fundamentally based on spread spectrum technology.
GSM has slow data rate in network.	CDMA has fast data rate in network.
Less security in GSM.	More security in CDMA.
GSM uses EDGE data transfer technology.	CDMA uses EVDO ready data transfer technology which has faster data transfer.
As the GSM signals are concentrated in the narrow bandwidth, signals can be detected easily.	The signals cannot be simply and easily detected in CDMA.
GSM is roaming over 80% of the world’s mobile network.	CDMA is roaming exclusively in the United States, Canada and Japan.
GSM phones continuously emit wave pulses. Consequently, there is a requirement to diminish exposure to electromagnetic fields.	CDMA phones do not have these wave pulses.

GSM	碼分多址
GSM特別適用于SIM。	CDMA特別適用于耳機或電話。
GSM代表全球移動通信系統。	CDMA代表碼分多址。
技術支持FDMA和TDMA。	技術支持CDMA。
GSM基本上基于稱為載波的楔形頻譜。	CDMA基本上基于擴頻技術。
GSM網絡中的數據速率較慢。	CDMA在網絡中具有快速的數據速率。
GSM中的安全性較低。	CDMA中的更高安全性。
GSM使用EDGE數據傳輸技術。	CDMA使用了EVDO就緒的數據傳輸技術，該技術具有更快的數據傳輸速度。
由于GSM信號集中在窄帶寬中，因此可以輕松檢測到信號。	在CDMA中不能簡單容易地檢測到信號。
GSM正在漫游全球80％以上的移動網絡。	CDMA僅在美國，加拿大和日本漫游。
GSM手機不斷發出波脈沖。 因此，需要減少對電磁場的暴露。	CDMA手機沒有這些波動脈沖。

翻譯自: https://www.includehelp.com/dictionary/sim-full-form.aspx

sim800 模式切換