GSM is 2G network, the last communication era of brilliance, 3G ERA network architecture is GPRS, the network is the difference between the GPRS in the network structure to add the packet domain (PS), GSM network architecture is the circuit domain, the process of communication has occupied the channel; 3G era is the internet era, CS (circuit Switch) in a way that consumes too much of the resource, PS (Packet Switch) is the way to release the channel after the packet content Exchange is complete, the billing method is calculated according to the traffic, more in line with the requirements of the 3G era. The GPRS network consists of three parts: Ue,utran and CN.
The CN organic part of the GPRS network consists of:
- MSC (mobile Switch Center), is the core of GPRS, it undertakes the routing information, including trans-MSC, such as the high-speed road junction, you go to the development zone or to Dalian? Data to MSC, with MSC to start, provide travel routes;
- Gmsc (Gateway Mobile Swift Center), mobile Switching center gateway, which mainly carries the routing function, this node is an optional node, when the number of MSC is small, one of the MSC can be used to assume the routing responsibilities, but with the increase in the number of MSC, Determine if the route is switched between multiple MSC (one where the appropriate route is not found, switch to the next MSC), the time cost is too high, based on a role on the MSC: Gmsc, mainly responsible for the data routing;
- VLR (Visitor location Register, visitor position Registration)/HLR (Home location Register, head Office registration), HLR is a data warehouse that stores information about a user, out of the function of providing the database and providing the corresponding services, Including the current geographical location, enjoy the service; VLR is more like Memcache, a cache of user information, when the user first starts up, returns to HLR for information (based on the information stored in Gsim), and then places the information in the VLR of its area, a cache of HLR, The future of continuous calls, you can get information in the VLR can be. Once the user submits the location information to display has left the current region, VLR will then delete the information of the record, so VLR just to be able to quickly communicate the establishment of a "hotel" for everyone to use temporarily, HLR is home, so called HLR still have a certain meaning.
- SGSN (Service GPRS supporting node, GPRS service support node), packet business processing, MSC, gmsc and VLR These are the circuit domain, HLR is actually GSM original PS inside role, but since the introduction of PS, HLR will be shared with CS. SGSN actually still need to synchronize some MS information with MSC, such as LA information of MS;
- GGSN (Gateway GPRS supporting node, GPRS gateway support nodes), GGSN function and gmsc function is basically consistent, mainly responsible for routing, and Internet, PSTN, fixed network and other network interaction, provide routing;
Utran Architecture
- RNS (Radio network Subsystem, wireless networks subsystem), is a bearer concept (container), and there is a scope limit, a RNS range is a cell; the subsystem is composed of the RNC and Node B subordinate to the RNC;
- The RNC (Radio network Controller, the wireless networking controllers), is responsible for the message forwarding and management, processing, including cross-cell routing implementation;
- Node B is the base station, modulation and demodulation, RF amplification, transceiver and other functions;
?
UE structure
- ME (Mobile Equipment), portable devices, such as mobile phones, can provide and wireless network connection function;
- GSIM (GPRS Subscribe identity Module,gprs Subscription identification module), that is, the SIM card inside the phone, used to identify the UE user identity, such as you have a mobile card, you can call, booking service (caller ID, missed call SMS reminder, etc.), When you enjoy these services because your SIM card has your identity, when you apply for these services, you will submit these applications (including your identity) to SN through RNs, the AUC trial, and through the HLR query confirmation, you can use.
One of the key technologies of Internet of Things
