LTN(Low Throughput Network)





Overall Network Architecture 


LTN Network Architecture is also very similar to other celluar network (e.g, LTE, WCDMA etc). They just use a little bit different names for each network components.

Assuming that most of the readers are more familiar with cellular network (e.g, LTE, WCDMA), I would try to put some comments on this network comparing LTE network.

In LTE/WCDMA, you would first have a user device to be camped on to a network. We call this user device as 'UE' or 'Mobile Phone'. In LTN, the component corresponding to UE is LEP (LTN End Point).

And then, in LTE/WCDMA, the UE first communicate to the Access Network called 'eNB' or 'BTS'. The component corresponding to eNT/BTS in LTN is called LAP (LTN Access Point).

Then in LTE/WCDMA, there is some intermediate components between Access Network and Corenetwork like MME, SGW/PGW, or SGSN/GGSN, but I don't see any intermediate compoments like this in LTN. In this sense, we can say LTN Architecture is simpler than the wide scale cellular network (LTE/WCDMA Network).

In backend, there usually be various kinds of Authentication Center, Application Servers in Cellular network. Similary, in LTN there are various Servers like LTN Server, CRA, OSS/BSS. LTN Server is working as data traffic center and CRA can be a kind of Authentication Center and OSS/BSS can be a policy handling center.

Overall network architecture is illustrated as follows. This is based on ETSI GS LTN 003 Figure 1.


LTN Interplay with Cellular Network


It would be possible to cover all the area globally (or nation wide) with the network architecture we described in previous section ?


I think it is possible technically, but questions is 'how about in business point of view ?'. As you know, deplaying any kind of wide scale network (Nationwide or Global) get various kinds of business factors.

So in more practical approach would be to deploy/implement LTN in a restricted/local area and connect it to an existing/wide scale cellular network to get all of these LTN globally connected to each other.


Another reason for coorperation of LTN and Cellular network is (according to ETSI GS LTN 003) : LTN could coorperate with cellular networks to address use cases where redundancy, complimentary or alternative connectivity is needed.


One of the possible configuration of combining LTN and Celluar Network is suggested as follows (from ETSI GS LTN 001 Figure 3).