PREFACE

 

This article is dedicated to various aspects of trends and possible development of Wireless Networks.

 

It’s nothing new in terms of technologies, but it’s full of quite fresh ideas, in terms of operations and subscribers usability. So, if you are quite familiar with technical aspects, then you can directly start reading from the partition “OPERATIONS /USABILITY”.

 

CONCEPT

 

First of all let’s try to determine clear meaning of all such terms of modern and future networks. Will start from the past and will finish by the future.

  

·          2G – whatever related to such technologies as GSM, GPRS, EDGE, CDMAone. Originally it is circuit switching network with packet switching addition. Access speed is less than 0.3 Mbit/s.

·          3G – CDMA 2000 EV-DO, WCDMA, HSPA. Same concept of mix circuit and packet switching network. Access speed (typical) is vary from 2 to 8 M bit/s.

·          4G – something related to higher speed, compare to 3G. Meantime there was quite popular concept that 4G is some network with ability of cross radio-network roaming and/or with peer-to-peer connections. Network is supposed to be packet switching only. Access speed is around 10 Mbit/s typically and up to 100 Mbit/s in theory.

·          5G – concept of very high speed radio access packet network. Considering that it is some further development of HSPA with access speed higher than in DSL technologies – 150 - 350 Mbit/s.

 

TECHNOLOGIES

 

·          NGN (Next Generation Network) – transformation of transport layer for 2G and 3G networks (along with wireline phone networks) from TDM to IP networks and introducing concept of splitting Switching Center to Call Server and Media Gateway. With NGN are appeared such technologies and protocols as H.248, GCP, BICC, IPv4, IPv6 and IP packet codecs.

 

·          IMS (IP Multimedia Sybsystem) – further development of NGN to reach so-called All-IP network. In ultimate variant ALL-IP means that all the elements in the network (including mobile terminals, base stations and IN platforms) are used IP network only. It means, for example that voice to IMS mobile phone is transferred as IP codec over packet network, and coding/decoding of packets is performed in the exact mobile phone, while these packets are transporting without any change over radio network, transport network and switching system. Considering as necessary “bridge” from 3G to 5G transformation. Same concept is valid for wireline networks, where fixed terminals are connected over IP network.

 

·          HSPA (so-called 3.5G) is the enhancement of WCDMA technology for packet network access only with access speed 10-20 times higher than original WCDMA (384 Kbit/s vs 7.2 Mbit/s).

 

·          EV-DO – analogue of HSPA, but used in CDMA 2000 networks. Access speed is risen from 153 Kbit/s to about 3.6 Mbit/s, compare to the original CDMA 2000 1x.

 

·          LTE – concept of the packet radio access technology which is compatible with 3G and IMS infrastructure. Can be done separately as Internet access network or as a part of 3G network. As stated in documentation - access speed is 100 to 326 Mbit/s. At present time LTE is supposed to be 5G.

o         Frequency: 2 – 20 GHz

o         Transmitter coverage: optimal – 5 km, but up to 70 km for rural area

o         Development is leading by main telecom vendors – Ericsson, Huawei, Nokia-Siemens.

 

·          WiMAX – packet access radio network which is based on technology similar to Wi-Fi. Since the beginning this technology is considering as access to internet, without any tie to voice networks. Access speed is 10 – 30 Mbit/s. At present time WiMax is considered as 4G technology.

o         Frequency: 2-6 GHz

o         Transmitter coverage: up to 5 km (for 802.16e standard – Mobile WAN)

o         Development is leading by Intel Corporation.

 

 

OPERATIONS / USABILITY

 

When experts are trying to compare HSPA/LTE and WiMax, they have the following pro et contra:

·          WiMax has less coverage per one radio node,

·          WiMax has less access speed,

·          WiMax has less variety of frequencies for usage,

·          Finally, WiMax is came from IT world, not from Telecom World, and therefore it hasn’t support from mobile networks and terminals vendors, which leads slow mass production without benefits of the economy of scale.

 

Meantime there are another points to stress, caused by the correlation of LTE with 2G/3G networks. These are the following:

·          WiMax has not same rich roaming capabilities as LTE has. It caused by the fact, that LTE (via 2G/3G networks) is interconnected through HLRs (or HSSes) are historically already interconnected on the World-Wide level.

·          “Always Online” feature is more efficient to organize in LTE networks, as there is an opportunity to have short signaling messages over NGN infrastructure, that something have to be downloaded over high speed LTE network. WiMax hasn’t such slow secondary network and this leads to the following un-efficiency:

o         Reduce overall WiMax network capacity and maximum speed, as all terminals have to be registered in local WiMax cell.

o         Reduce battery charge in Mobile Terminals as WiMax electronics (transmitter, CPU and so on) consumes more power than similar of 2G/3G.

o         Limited access area – where WiMax network ends, then no any service available. Meantime for LTE some basic service (with lower speed) can be seamlessly provided over HSPA or even 2G network of the operator.

·          Unified common contact book – i.e. LTE subscriber have in one terminal opportunity to have access to any type contact like call to fixed PSTN number, call mobile, send SMS, access to e-mail, Instant Messaging and WEB accounts like blogs, chats, personal pages and so on. Meantime, WiMax subscriber has access (at least easy and cheap one) to packet network contact types only. Therefore generic communication channels like call phone number and send SMS are quite limited and local client software dependant abilities.