ZyXEL Communications ZyWALL USG 100 Series, Руководство пользователя

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Chapter 13 Interfaces
ZyWALL USG 100/200 Series User’s Guide
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If the signal strength of a 3G network is too low, the 3G card may switch to an
available 2.5G or 2.75G network. See the following table for a comparison
between 2G, 2.5G, 2.75G and 3G of wireless technologies.
To change your 3G WAN settings, click Configuration > Network > Interface >
Cellular .
Note: Install (or connect) a compatible 3G card to use a cellular connection. See
Chapter 57 on page 943 for details.
Note: The WAN IP addresses of a ZyWALL with multiple WAN interfaces must be on
different subnets.
Table 67 2G, 2.5G, 2.75G, 3G and 3.5G Wireless Technologies
NAME TYPE
MOBILE PHONE AND DATA STANDARDS
DATA
SPEED
GSM-BASED CDMA-BASED
2G Circuit-
switched
GSM (Global System for Mobile
Communications), Personal
Handy-phone System (PHS), etc. Interim Standard 95 (IS-95), the
first CDMA-based digital cellular
standard pioneered by Qualcomm.
The brand name for IS-95 is
cdmaOne. IS-95 is also known as
TIA-EIA-95. Slow
Fast
2.5G Packet-
switched GPRS (General Packet Radio
Services), High-Speed Circuit-
Switched Data (HSCSD), etc. CDMA2000 is a hybrid 2.5G / 3G
protocol of mobile
telecommunications standards that
use CDMA, a multiple access scheme
for digital radio.
CDMA2000 1xRTT (1 times Radio
Transmission Technology) is the core
CDMA2000 wireless air interface
standard. It is also known as 1x,
1xRTT, or IS-2000 and considered to
be a 2.5G or 2.75G technology.
2.75G Packet-
switched
Enhanced Data rates for GSM
Evolution (EDGE), Enhanced GPRS
(EGPRS), etc.
3G Packet-
switched
UMTS (Universal Mobile
Telecommunications System), a
third-generation (3G) wireless
standard defined in ITU
A
specification, is sometimes
marketed as 3GSM. The UMTS
uses GSM infrastructures and W-
CDMA (Wideband Code Division
Multiple Access) as the air
interface.
CDMA2000 EV-DO (Evolution-Data
Optimized, originally 1x Evolution-
Data Only), also referred to as EV-
DO, EVDO, or just EV, is an evolution
of CDMA2000 1xRTT and enables
high-speed wireless connectivity. It
is also denoted as IS-856 or High
Data Rate (HDR).
3.5G Packet-
switched HSDPA (High-Speed Downlink
Packet Access) is a mobile
telephony protocol, used for
UMTS-based 3G networks and
allows for higher data transfer
speeds.
A. The International Telecommunication Union (ITU) is an international organization within which governments and the private
sector coordinate global telecom networks and services.