Life is On the Road.

联通似乎封了我网站的ip，用电信访问博客正常，联通3g无法访问，也ping不通。不知什么原因，希望过段时间能恢复。
目前还能通过opera访问，opera的代理服务器真是靠谱！
目前我的联通3G也能访问了，就是灰常的慢:(

联通，至少在南山，经常有信号也连不通，有效办法是先开offline再恢复正常模式，信号时好时差，长期使用必然忍无可忍。
移动，edge上网的同时能拨打电话，而理论上2g网络是不能同时上网和打电话的，不知道深圳移动缘何出现如此奇迹。

今天来到深圳老蒋家，小区信号不太好，3.5g信号时有时无。Nokia E52遇到了彩信发不出去的问题——之前只收彩信，没有发过彩信。网上搜了一下，遇到类似问题，修改彩信接入点为uniwap之后可以收发彩信，但是速度很慢……记得之前3gwap接入点是可以收彩信的。
其他人有类似问题么？

http://bbs.dospy.com/thread-3915134-1-1.html

联通WCDMA 3G上网以及彩信设置

注意：彩信里头接入点不能设置为3gwap，我设置了怎么也收不到彩信，改成uniwap才行，好像2g时代也是这个uniwap，以前没用过联通的。。。。。。

近日困惑全球手机制式频段的问题，查了些资料，整理在此。以wikipedia和nokia官网为准。

1. G：generation，代，技术上的更新换代。xG表示x代，简单明了，没有其他含义。具体2G，2.5G，3G……的含义见下文。
   UMTS: Universal Mobile Telecommunications System，http://en.wikipedia.org/wiki/UMTS

   Mobile telephony and mobile telecommunications standards
   0G (radio telephones)	MTS • MTA · MTB · MTC • IMTS • MTD • AMTS • OLT • Autoradiopuhelin
   1G	NMT · AMPS · Hicap · Mobitex · DataTAC · TACS · ETACS
   2G	GSM/3GPP family GSM · CSD 3GPP2 family CdmaOne (IS-95) Other D-AMPS (IS-54 and IS-136) · CDPD · iDEN · PDC · PHS
   2.5G	GSM/3GPP family GPRS · HSCSD iDEN family WiDEN
   2.75G	GSM/3GPP family EDGE/EGPRS 3GPP2 family CDMA2000 1xRTT (IS-2000)
   3G (IMT-2000)	3GPP family UMTS (UTRAN)  · WCDMA-FDD • WCDMA-TDD • UTRA-TDD LCR (TD-SCDMA) 3GPP2 family CDMA2000 1xEV-DO (IS-856)
   3.5G	3GPP family HSDPA · HSUPA 3GPP2 family EV-DO Rev. A
   3.75G	3GPP family HSPA+ 3GPP2 family CDMA2000 3x (EV-DO Rev. B)
   3.9G (Pre-4G)	3GPP family LTE (E-UTRA) Other Mobile WiMAX (IEEE 802.16e-2005) · Flash-OFDM · IEEE 802.20
   4G (IMT-Advanced)	3GPP family LTE Advanced WiMAX family IEEE 802.16m
   Related articles	History · Comparison of standards · List of standards · Spectral efficiency comparison table · Cellular frequencies · Cellular network theory · Mobile broadband

2. 关于频段：
   Quad-band，四频，GSM 850/900/1800/1900。经常提起的四频手机，适应全球制式，仅限于2G技术，也就是语音通话。我们需要关注的是3G技术，用于处理数据传输。而一般的3G手机都是支持2G四频段的。

   详细资料，http://en.wikipedia.org/wiki/Quad-band

   WLAN

   A technique to combine the 2.4 GHz and 5 GHz band to give a theoretical bitrate of 600 Mbps.

   2G

   GSM frequency bands The GSM standard originated in Europe, where mobile phones occupy two frequency bands: one in the 900 MHz range and one in the 1800 MHz range. When GSM technology crossed the Atlantic to the Americas, it was impossible to reuse the same European frequency bands since those had already been allocated to other devices by the FCC. Hence, a different pair of frequency bands were made available for GSM use: the 850 and 1900 MHz bands.

   In summary, a quad-band mobile phone is used to designate a phone that can operate in the following GSM frequency bands:

   • 850 MHz (U.S./Canada/Latin America/Brazil (Only the carrier Vivo in the south and south-east of Brazil))
   • 900 MHz (Africa/Europe/Brazil/Australia/Asia (ex Japan and S. Korea))
   • 1800 MHz (Africa/Europe/Brazil/Australia/Asia)
   • 1900 MHz (U.S./Canada/Latin America/Brazil (Only the carrier Vivo in the north, north-east and centre-west of Brazil))

   Some companies refer to this feature as “World Phone”, due to the variety of bands a quad-band phone supports.

   Note that hardly any quad band phones cover GSM-450, a band used in sparsely populated areas or in less developed countries due to its longer range. While a “quint band” phone (450/850/900/1800/1900) is possible, none have yet been announced.

   3G

   Further information: UMTS frequency bands

   UMTS / HSDPA / HSUPA devices operate in the UMTS frequency bands 800/850/1900/2100 or 850/1700/1900/2100 MHz:

   • 2100 (downlink) / 1900 (uplink) for Europe, Africa, Australia, New Zealand, Asia (including South Korea and Japan) and Brazil (usually referred simply as UMTS2100)
   • 1900 for North and South America
   • 2100 (downlink) / 1700 (uplink) for WIND Mobile and T-Mobile USA, called AWS Band (usually referred simply as UMTS1700)
   • 900 for Australia (Optus and Vodafone Australia in rural areas), Vodafone New Zealand and in the future in countries that currently use GSM900
   • 850 for North and South America, Australia (NextG), New Zealand (Telecom XT)
   • 800 for Japan (NTT DoCoMo in rural areas)

   Note that being UMTS / HSDPA / HSUPA quad band doesn’t mean that phone is a GSM / GPRS / EDGE quad band. However nearly all HSUPA quad band devices are EDGE quad band too.

   Five and Six band phones (800/850/900/1700/1900/2100) are possible but none have been announced.

3. 关于中国3G的频段：中国电信获得1920-1935MHz和2110-2125MHz频段，中国联通1940-1955MHz和2130-2145MHz频段，而中国移动获得的频段是1880-1900MHz和2010-2025MHz，其3G标准是基于TDD模式的。
   需要注意：2100MHz只是一个标准，并不是说仅支持2100MHz，联通的频段是完全符合2100Mhz范围的。具体范围懒得查了。
4. 关于Nokia：同一款手机以小型号代表销售地区不同，而支持的WCDMA网络频段也不同。在Nokia手机输入*#0000#可以查到具体小型号。
   以风靡全球的E71为例
   # E71-1 Quad-band EGSM 850/900/1800/1900, WCDMA 900/2100 HSDPA
   # E71-2 Quad-band EGSM 850/900/1800/1900, WCDMA 850/1900 HSDPA
   # E71-3 Quad-band EGSM 850/900/1800/1900, WCDMA 850/2100 HSDPA
   水货的E71如果不幸买到了美国版本E71-2是无法支持国内联通的WCDMA频段的。

   以我关注的E52为例，这个机器没有发行美国版本
   # WCDMA 900/2100 (Nokia E52-1)
   # WCDMA 850/2100 (Nokia E52-2)
   无论购买哪里的E52机型，都能支持联通的WCDMA频段，同样都不可能在美国使用。

   Nokia E系列更多资料：http://en.wikipedia.org/wiki/Nokia_Eseries

   顺便说一下iPhone，同时支持850/1900/2100MHz频段，可以在中国，美国和欧洲通行使用3G。

5. UMTS技术和频段的其他资料，这里说的远不如wikipedia清楚。

   http://www.umtsworld.com/umts/faq.htm

   What are the different types of 3G networks?

   ITU Recommendation ITU-R M.1457 specifies five types of 3G radio interfaces:

   • IMT-2000 CDMA Direct Spread, also known as UTRA FDD including WCDMA in Japan, ARIB / DoCoMo recommendation. UMTS is developed by 3GPP. • IMT-2000 CDMA Multi-carrier, also known as Cdma2000 (3X) developed by 3GPP2. IMT-2000 CDMA2000 includes 1X components, like cdma2000 1X EV-DO. • IMT-2000 CDMA TDD, also known as UTRA TDD and TD-SCDMA. TD-SCDMA is developed in China and supported by TD-SCDMA Forum • IMT-2000 TDMA Single Carrier, also known as UWC-136 (Edge) supported by UWCC • IMT-2000 DECT supported by DECT Forum.For more information about 3G air interfaces, download ITU “What is IMT-2000″ presentation (2.5Mb!). Note that page 3 does not classify CDMA2000 1X as 3G, but page 6 does. please see ITU presentation page. Some 2.5G systems (GSM GPRS, IS- 95B and CDMA2000 1X (?)) will be able to deliver 3G services, so it will be difficult for users to see the difference.

   What are the UMTS frequencies and channel spacing?

   1900-1920 and 2010-2025 MHz Time Division Duplex (TDD, TD/CDMA) Unpaired, channel spacing is 5 MHz and raster is 200 kHz. Tx and Rx are not separated in frequency
   1920-1980 and 2110-2170 MHz Frequency Division Duplex (FDD, W-CDMA) Paired uplink and downlink, channel spacing is 5 MHz and raster is 200 kHz. An Operator needs 3 – 4 channels (2×15 or 2×20 MHz) to be able to build a high-speed, high-capacity network.
   1980-2010 and 2170-2200 MHz Satellite uplink and downlink