Wireless Internet Service

Wireless Internet Service (CDMA 1x,GPRS,3G or EVDO)

One day customer services of the telecommunication operators received a call from a customer to complaint their data service. A customer said that they have lied to all their customers. Telecommunication operators promised to give us the best speed to their Wireless Internet Access through CDMA platform. But what customers get is not what they have been promising. Customer complaint since the Wireless Internet Access’ speed is very slow. Meanwhile another customer called to complaint with different cases. They have been trying so many times to connect data service of telecommunication operator but always failed. And finally they said that Wireless Internet Access offered by telecommunication operators is suck. It has more disadvantages rather than advantages.

I think whichever telecommunication operators that offer Wireless Internet Access CDMA, GPRS, 3G or EVDO will face the same cases; their will got a lot of complaint their customers. Some of customer’s complaint about the quality of speed, some about network availability and some about tariff that charged to them. Everyday we can see in the news paper regarding to this complaint. They releases a complaint to news paper due to after several complaint they have done to telecommunication operators, there is no improvement. They still face the same problem. Many customers disappointed to Wireless Internet Access offered by several telecommunication

Actually many factors are influence the quality of data service offered by telecommunication operators, CDMA, GPRS, 3G or EVDO. Data service more complicate than voice or SMS services. Many network elements are involved to have data service to their customers. Generally to have voice or SMS service, the network element that involved to these services are;

1. Customers’ handset/mobile phone
2. Base Transceiver Station (BTS)
3. Transmission link
4. Core Network (Mobile Switching Centre (MSC), Home Local Register HLR)
Meanwhile in data services, many others networks are needed in order to this service and as the result new additional network elements will influence the quality of service

In order to have data service (Wireless Internet Access), telecommunication operator must add several networks elements to existing network;
1. Modem to dial up or mobile phone with internet features
2. Internet link to Internet Service Provider (ISP)
3. Connection from telecommunication operators’ office to ISP
4. International connection from ISP to world wide

The problem of Wireless Internet Service could be from any side mentioned above and we need to analyze each complaint deeply to identify from which element the problem coming is and getting the best solution. It is totally different with SMS or voice service once the problems come. The problem could be from customers’ side but since customers did not know a lot about it, they do nothing in their side to resolve the problem. But mostly, the problem of Wireless Internet Service is coming from telecommunication operators’ end. And in some case, it is coming from their ISP partners.

Architecture Network of CDMA 2000

Architecture Network of CDMA 2000

Network architecture of CDMA 2000 in general can be explained as in figure below where The Radio Access Network (RAN), in CDMA2000 networks consists of multi Base Station (BS) each connected to a Radio Network Controller (RNC) or Base Station Controller (BSC). RNC manages several concurrent Radio Link protocol (RLP) layer-2 session with Mobile Node (MN) and performs per-link bandwidth management functions. The 144 kbps per carrier throughput in 3G-1x is shared among multiple active MN, though at any given instant, a single MN may be allocated full data rate. When a MN moves from one RNC to the other, the on-going RLP session is torn down and a new session is established with the visited RNC.

The Packet Data Serving Node (PDSN) in the architecture aggregates data traffic from multiple RNC and interfaces the RAN to a packet switched network. The PDSN terminates a Point-to-Point (PPP) connection and maintains session state for each mobile node (MN) in its serving area. By keeping PPP connection alive, MN will have a better quality of service.

The PDSN is required to support two modes of IP operation: Simple-IP and Mobile-IP. In Simple-IP mode, if MN moves from one PDSN to another, the PPP connection must be re-established, and new IP address is required. This requires the user to re-establish all their data sessions. In the Mobile-IP mode, the PDSN implements the Foreign Agent (FA) functionality allowing cross PDSN mobility.

Network of CDMA2000 have components as following:

• Mobile Station (MS)

Wireless devices above are integrated into Mobile Station (MS) or Mobile Node (MN) with primary function to conduct, maintaining and terminating the access connection (voice and data) to network. MS build connection by requesting Radio Channel to RN. After the connection was established, MS will responsible for maintaining that radio channel and buffering packets if the channel was unavailable. MS usually support for encryption and protocols such Mobile IP.

• Radio of Network ( RN)

Consists of Base Station Transceiver Subsystem (BTS), Packet Control Function (PCF), and Base Station Controller (BSC). BTS has a function to control the MN connection within coverage area and manage data distribution to all connected MN. Primary functions of PCF are to establish, maintain and terminating a connection with Packet Data Serving Node (PDSN). PCF communicate with BSC for requesting and managing radio channel to perform packet transmission from MS and vice versa. PCF is also responsible to collect accounting information and towards it to PDSN.

• Home Agent ( HA)

HA has a function in Mobile IP implementation by tunneling packets to Foreign Agent (FA) and vice versa. HA provides secure connection by conducted MS authentication through Mobile IP registration. HA also maintain the connection with AAA to have user profiles.

• Authentication, Authorization And Accounting ( AAA)

AAA have different function depend on network type where it connected to if AAA server was connected to service provider network, then the primary function are overcoming request of authentication from PDSN to Home IP network, and authorize responses from Home IP network to PDSN. AAA also stores accounting information of MS and provide user profile and QoS information to PDSN. If AAA server connected to Home IP network, it conducts MS authentication and authorization as local AAA request. If AAA connected to broker network, it forward request and response between service provider network and Home IP network which not directly connected.