Mobile phones had a long history. The last three decades of mobile phones is quite amazing. Check out this infographic.
Author Archives: 3gLteInfo
Multi-Carrier Heterogenous Networks (HetNet) Performance
Heterogeneous networks (HetNets), consisting of Macro NodeBs (macros) and low power Pico NodeBs (picos), can increase system capacity by offloading some users to the picos. However, this offloading may be limited due to intercell interference from macros to picos that reduces their coverage. HSPA Multi-carrier HetNets allow the use of range expansion techniques to achieve more offloading, such as power reduction from the macros on one carrier. “Performance Analysis of HSPA Multi-Carrier Heterogenous Networks” white paper provides a system level analysis of the gain provided by power reduction on one carrier of the macros in a HetNet environment. As the interference from the macros is reduced, more capacity offloading to picos occurs and higher system capacity can be achieved. By considering cell biasing in serving cell selection, further gains can be observed.
Huawei, Qualcomm Completed LTE CSFB (Circuit Switched Fallback) to UMTS Testing
Huawei and Qualcomm have completed an LTE FDD flash CSFB (Circuit Switched Fallback) voice call to UMTS using R9 protocol and Qualcomm’s Snapdragon S4 processor, the MSM8960, during a series of optimisation tests.
The tests, based on the flash CSFB voice service for the R9 protocol, resulted in low call setup latency than that of the R8 protocol, and close to that of a native UMTS voice call. During the CSFB testing, which also included LTE TDD calls, good call setup times were seen for both UMTS and GSM.
The introduction of R9 CSFB will further enhance users’ experiences and enable voice services on their LTE-based smartphones, through CSFB to GSM and UMTS. The joint CSFB testing was part of an ongoing cooperation between Huawei and Qualcomm on interoperability testing and optimisation involving GSM/UMTS/LTE TDD/FDD technologies.
Huawei’s LTE CSFB service has been commercially deployed in the Middle East, Asia Pacific, Europe and other regions, allowing users to access LTE data and voice services.
IP Multimedia Subsystem (IMS) Emergency Sessions – Part 1
Non Voice Emergency Service (NOVES ) allows the UE to use other media and communication types other than voice and GTT during an IMS emergency session when the network supports IMS emergency service and the UE also supports other media or communication types.
In case of Emergency session over IMS, Emergency sessions should be prioritized over non-emergency sessions by the system.
Emergency Service is not a subscription service and therefore, when the UE has roamed out of its home network, emergency services shall not be provided by the home network and shall be provided in the roamed-to network if the roamed-to network supports emergency sessions. If a UE has sufficient credentials, it shall initiate an emergency registration with the network (requiring the involvement of the home network). The CSCFs providing service for emergency sessions may be different from the CSCFs involved in the other IMS services. If the registration fails, the UE may attempt an anonymous emergency call.
When a UE performs an emergency registration, barring and roaming restrictions are ignored.
If the UE has location information available, the UE shall include the location information in the request to establish an emergency session. The location information may consist of network location information, that is the Location Identifier, and/or the Geographical location information.
The P‑CSCF may query the IP‑CAN to obtain location identifier.
In can of IMS emergency service the UE should be able to access the IP-CAN without sufficient security credentials.
IMS Emergency Service Architecture
NOTE:
P‑CSCF, EATF and E-CSCF are always located in the serving network.
Based on operator policy, the E‑CSCF can route the emergency IMS session to the PSAP via an ECS
UE
The UE should able to detect emergency session establishment request. If an incoming call has an emergency call back indicator present, the UE shall detect the incoming PSAP call back session establishment request.
Proxy‑CSCF
Proxy‑CSCF handle registration requests with an emergency registration indication like any other registration request, except that it may reject an emergency registration request if the IM CN subsystem that the P‑CSCF belongs to can not support emergency sessions for the UE.
For non-roaming subscribers, the P-CSCF may forward an emergency session to an S-CSCF if so instructed by operator policy or local regulation.
Emergency‑CSCF
Emergency‑CSCF receives an emergency session establishment request from a P‑CSCF or an S-CSCF. If the UE does not have credentials, a non-dialable callback number shall be derived where required by local regulation.
If location information is not included in the emergency request or additional location information is required, the E‑CSCF may request the LRF to retrieve location information as described in clause 7.6 Retrieving Location information for Emergency Session.
Location Retrieval Function (LRF)
Location Retrieval Function (LRF) is responsible for retrieving the location information of the UE that has initiated an IMS emergency session.
LRF utilizes the a Routing Determination Function (RDF) to provide the routing information to the E‑CSCF for routing the emergency request.
Serving-CSCF
When the S‑CSCF receives an Emergency Registration, the S‑CSCF determine the duration of the registration by checking the value of the Expires header in the received REGISTER request and based on local regulation or operator policy of the serving system.
MGCF
The MGCF may:
- Determine based on the operator policy if an incoming call form the PSTN is for the purpose of PSAP call-back. The operator policy decision may be based on that the call is from an emergency centre or from a PSAP and/or any other information made available to the MGCF.
- Include a “PSAP call-back indication” in the SIP session establishment request if an incoming call is determined to be for the purpose of PSAP call-back.
Reference
3GPP 23.167 – IP Multimedia Subsystem (IMS) emergency sessions
Minimization Of Drive Test Requirements Analysis
Wireless network is one of the most complex system and to make sure that the Network is working as per the standards and serving the users optimally, the telecom operators perform drive tests. These tests are carried out for different reasons, some times to optimize the network and some other times to debug certain issues in a particular area.
The repetitive drive tests are a big bottleneck to the network operator in terms of money spent for carrying out the operation and the time spent to debug certain issues. To minimize these 3GPP standardization groups proposed new techniques to minimize the amount of drive tests by collecting information from mobile users. The information can be on different kinds of measurements, handovers, or signalling failures.
There are two different type of MDT (Minimization of Drive Test)
Immediate MDT
MDT functionality involving measurement performance by UE in CONNECTED state and reporting of the measurements to eNB/RNC available at the time of reporting condition.
Logged MDT
Where UE log in idle mode together with time stamps and optionally with accurate location information.
Requirements for minimization of drive test
Minimization of drive test should follow the following requirements.
UE measurement configuration
The operator can bale to configure an UE measurements for logging purpose independent from the NW configurations. This is done for Radio Resource Management (RRM) purpose.
UE measurement collection and reporting
The time interval for measurement logs collection and reporting shall be configurable in order to limit the UE battery consumption and network load.
Geographical scope of measurement logging
This requirement says that the operator should able to configure the geographical area where the defined set of measurement can be performed.
Location Information
The measurements in the measurement logs should be connected to the location information.
Time information
The measurements in measurement logs shall be linked to the time stamp available in the UE.
Device type information
The terminal type and the capabilities of the UE should be correctly indicated to the NW so that the operator can select correct terminals for specific measurements.
Dependency on Self Organizing Network (SON)
The solutions for minimization of drive test shall be able to work independently from the SON support in the network.
References
- 3GPP TR 36.805 – Study on Minimization of drive-tests in Next Generation Networks
- 3GPP TS 37.320 – Universal Terrestrial Radio Access (UTRA) and Evolved Universal Terrestrial Radio Access (E-UTRA); Radio measurement collection for Minimization of Drive Tests (MDT); Overall description; Stage 2 (Release 10)
Rohde & Schwarz Tests VoLTE and Audio Quality
Rohde&Schwarz demonstrated voice over LTE (VoLTE) and audio quality measurements with the R&S®CMW500 wideband communication tester and the R&S®UPV audio analyzer at LTE North America 2011. For the demonstration a commercial LTE USB dongle in collaboration with an IMS client running on a PC was used to simulate a VoLTE-capable device. This setup registered to an IMS server via LTE to establish an IMS call. The audio quality measurements carried out have been in line with the PESQ® standard.
Rohde&Schwarz also demonstrate the SMS over IMS Verification.
Will Nokia’s 2011 Results Bring Some Hope?
Nokia will publish its fourth quarter and 2011 years result on 26th January 2011. Since the last few years the largest Mobile Phone manufacturer in the world is struggling a lot due to strong competitions from smart phone manufacturers like Apple and Samsung. It is not only the smart phones but Nokia’s feature phone segment is now in trouble as many cheap vendors are eating up its market shares from Nokia’s favorite marketplaces like India and Pakistan.
Among all this darkness Nokia did some really good changes in their ways of working, like making Microsoft’s mobile platform as their primary mobile OS. The other good move was Nokia’s alliance with many operators in North America where its market share is not so great. In the US, Nokia has now partnered with At&T and T-Mobile. With AT&T Nokia offered it’s Lumia 900 smart phones while with T-Mobile the Lumia 710 smart phones. Both of these smart phones are powered by the Microsoft’s Mobile OS, which will tap into a niche market. Though the smart phones were not a game changer for Nokia but good reviews by media and consumers definitely gave some boost Nokia’s dooming business.
The 2011 third quarter results of Nokia were not so impressive, but the best thing about Nokia is that they already figured out where they are losing and where to improve.
Apart from smart phones and mobile handset business, Nokia has another big struggling unit, Nokia Siemens Network. On its part Nokia Siemens Network has also made some good moves last year like buying the Motorola Networks and increasing their footprint in the US market. With a reported 17000 cuts many in the services business unit, the focus for them remains on mobile broadband R&D. They face strong challenges from their Chinese counterparts especially since Motorola was using Huawei as its supplier for the radio, it is anybody’s guess the complexities this might lead to between NSN and Huawei.
During the last year Nokia delisted itself in numbers of stock exchanges like Frankfurt, London, Paris and Stockholm Stock Exchanges. Which is surely a big concern for its share holders around the world.
But after all these Nokia needs to take better decisions to make it’s loyal costumers and share holders happy.