why nokia is using st ericssons novathor arm chip instead of qualcomm

Great stuff for understanding more about different smartphone platforms :)

why-nokia-is-using-st-ericssons-novathor-arm-chip-instead-of-qualcom

Heterogeneous networks (hetnets)

The following is a summary of an article in ericsson review  December 28, 2011

In locations where the number of users are high a densified infrastructure can provide the increase in NW capacity that is needed. This can be achieved with a layered cell structure meaning that multiple and equally available cells have overlapping coverage areas.  Typically, the traditional macro cell transmitting with high power over a large coverage area is complemented with pico cells transmitting with low power over a smaller coverage area that is geographically covering a part of the coverage area of the macro cell. In addition to simply selecting the cell with the strongest signal, the cell selection algorithm should in this case  also incorporate cell congestion and backhaul capacity. Heterogeneous network deployment can be achieved with two different approaches, resource partitioning and soft-cell  schemes:

·         Resource partitioning can be achieved in either the frequency or the time domain which in reality creates separate cells with individual system information and synchronization signals transmissions.

·         In shared cell or soft cell schemes, the low power pico cells are part of the macro cell but with a Cell Specific Reference signal (CRS) which determines which part of the System Information that is relevant. Also, a Demodulation specific Reference Signal (DM-RS) is used to determine which transmission point (macro or pico cell) the terminal should use.

Heteroge­neous deployments that use soft cells can provide greater mobility robust­ness than deployments with separate cells. This is important, especially when moving from a low-power node to the macro. In separate cell deployment, a handover procedure is required to switch serving cells. If, during the time it takes to perform the handover procedure, the terminal has moved too far into the macro area, it may drop the downlink connection from the low-power node before handover is complete – leading to a radio-link failure. In soft-cell deployment, the transmission point that should be used for downlink trans­mission can be changed rapidly without a handover procedure – thus reducing the probability of dropped connections.

the article in its entirety can be found at
heterogeneous_network_deployments_lte

I dont think so..........

mo bizniz for STE as Sharp releases new smartphones based on Thor M5730 thin modem

http://www.stericsson.com/press_releases/PR_Sharp_Thor.jsp

Short summary of the functions and features of MIMO

Multiple Input Multiple Output (MIMO) may in a most generalized way be viewed as the use of pre-coding with multiple antennas at both the transmitter and the receiver arranged to operate in one of the 2 following ways: 

• Single stream: both diversity and array (beamforming) gain can be accomplished for increasing the carrier-to-interference-ratio which is typically used in bad channel conditions or at the cell edge borders for increased coverage. The pre-coding weights are selected such that the data streams from the two antennas can be combined coherently into a single stream. A new and modified type of CQI is used that consists of 5 bits carrying the Pre Coding Information (PCI) and the CQI itself.
• Dual stream: Transmission in multiple layers or streams for increasing the maximum achievable data rate. This is also known as spatial multiplexing and requires high carrier-to-interference-ratio and is therefore typically only used near the nodeB and in good channel conditions. Pre-coding is used in this case to create two orthogonal data streams that can carry separate flows of information. By choosing the weights for the second stream as the orthogonal eigenvectors of the covariance matrix at the receiver, the two streams will not interfere with each other and the bit rate may be doubled in this way. The physical layer HARQ processing for each stream is identical to the single stream case meaning that one ack/nack is transmitted for each stream. The CQI in this case has been extended to 8 bits and contains separate information for each flow.

All devices supporting MIMO has to be capable of receiving 15 channelization codes. The system has been extended in later/coming releases for higher number of layers/ranks each requiring an additional pair of transmit/receive antennas and allowing for a doubling in the bitrate for each doubling in the layers/rank.  

Goodbye to Ericsson Mobile Broadband Modules!

2011/12/notebooks-still-dont-have-3g-modules

System Architecture Evolution

Functional split between RAN and CN

• For WCDMA/HSPA, the philosophy behind the functional split between RAN and CN is to hide all the radio interface functionality from the CN meaning that, any radio access technology can be used with the same CN
• The LTE RAN builds on the same philosophy as WCDMA/HSPA with an added key design feature, to minimize the number of nodes.

WCDMA/HSPA RAN

• In HSPA, the node B handles all physical layer functions except for macro-diversity which is handled by the RNC
• Serving and drift RNC is one way of handling a terminal that has moved to a cell that is under another RNC. Another way is SRNS relocation.
• In addition to macro-diversity, security functions is another reason for keeping the RNC since the large number of nodeB’s and the sometimes hard-to-protect locations they are used in is considered to make them unsafe for hosting sensitive functionality.

LTE RAN

• For LTE, it was decided that the gains of keeping the RNC does not motivate the increased complexity and so, it was removed along with macro-diversity.
• The e-nodeB is connected to the CN using the S1 interface. The e-nodeB’s are interconnected using the X2 interface which is mainly used for connected mode mobility.

Evolved Packet Core(EPC)

The nodes for the Evolved Packet Core is:                                                                                  

• Mobility Management Entity(MME): this is the control plane node
• Serving Gateway: this is the user plane node that connects the EPC to the LTE RAN
• Packet Data Network Gateway(PDN Gateway): this is the user plane node that connects the EPC to the Internet

·         S1 flex enables a more robust network. If one of the EPC nodes becomes unavailable another one can cover in its place

·         EPC does not only connect to 3GPP RAN’s. In particular, WIFI, WIMAX and CDMA2000/EV-DO access support is planned.