[Nexus 4 Q&A, Help & Troubleshooting] pflatlyne:
The prevailing wisdom on the LTE capabilities of the Nexus 4 is that it is a leftover artifact from its parent Optimus G design and that its missing components and somehow inferior to a "real" LTE phone,simply an accident that "sort of works".

However,I'm not convinced of this. I downloaded the Nexus 4 E960 service manual,as well as the E970,E973 and E975 service manuals. Upon a careful analysis of the differences,there were not a lot. There most notable deletion was bands 7 and the hardware for band 17/20. As far as 17/20 is concerned,you can have one but not the other. They are mutually exclusive. Similarly,bands 2 and 3 are mutually exclusive. What was evident was that the Optimus G was a modular design where there are selections of which components to include in an otherwise identical design to chose the supported frequencies. Considering the number of Optimus phones to support all the different networks,my guess is that the real reason for lack of LTE is the inability of the basic design to support LTE in all the markets,and therefore the potential confusion and from a marketing perspective,the feeling that "The nexus 4 isn't really supported here" in the markets where its LTE wont work. People dont like paying full price for a phone,when they feel "half the features don't work on my network" But hardware wise,the Nexus appears no less capable of supporting LTE on any of the supported bands than any other LTE phone. The only really relevant band of course is band 4,which T-Mobile uses. Anandtech tested the phone with cellular diagnostic equipment and found that most other bands were NOT supported. The only reason I can see is that its not supported in software. The hardware should do it.

In short,here is what I found,hardware wise.

Service Band Function FreqRange Antenna ModemOutput

LTE B1 appears functional. Connects to the quadGSM/HSPA/LTE band 1/8 PAM. (This was a configuration choice the other choice was band 1/5) But B5 is configured on this phone on another PAM. This is seems unusual. The other Optimus phones seem to have 8 OR 5,but not both. This in itself reduces the possible other LTE bands that could be supported.

LTE B1 TX 1920-1980 ANT 2 TX_MB4

LTE B1 RX 2110-2170 ANT 2 PRX_MB3

LTE B1 DRX 2110-2170 ANT 6 DRX_HB

UMTS B1 TX 1920-1980 ANT 2

UMTS B1 RX 2110-2170 ANT 2

UMTS B1 DRX 2110-2170 AND 6

LTE B2 appears to all be there.

TX_MB3 connects to the antenna switch through a 1880Mhz saw filter ,then a APCM-5702 PAM,then to the siwtch and finaly the antenna.

PRX_MB2 connects to the antenna 2 switch.

DRX_MB connects to 1960Mhz saw filter before connectingto the switch and then antenna 6 (which in another place is called antenna 4,there are quite a few typos and holdovers from previous models)

LTE B2 TX 1850-1910 ANT 2 TX_MB3

LTE B2 RX 1930-1990 ANT 2 PRX_MB2

LTE B2 DRX 1930-1990 ANT 6 DRX_MB

UMTS B2 TX 1850-1910 ANT 2

UMTS B2 RX 1930-1990 ANT 2

UMTS B2 DRX 1930-1990 ANT 6

GSM High (this is distinct from the Band 2 paths,and runs to a GSM input on the quadGSM PAM.

PCS TX 1850-1910 ANT 2 TX_MB2

PCS RX 1930-1990 ANT 2 PRX_MB1

DCS TX 1710-1785 ANT2 TX_MB2

DCS RX 1805-1880 ANT2 PRX_MB1

This can never work when band 2 is chosen (unless another band was sacrificed) as there is a

1880Mhz saw filter in the way of the transmitter anda 1960 saw in the way of the receiver. You could

in theory have band 2 OR band 3,but never both. The DCS band uses the right frequencies,but is run through a GSM PAM so does not have the bandwidth.

LTE B3 TX 1710-1785 Ant 2 TX_MB3

LTE B3 RX 1805-1880 Ant 2 PRX_MB2

LTE B3 DRX 1805-1880 Ant 6 DRX_MB

UMTS B3 TX 1710-1785

UMTS B3 RX 1805-1880

UMTS B3 C 1805-1880

TX_MB1 goes to a saw filter. Its listed as 1747.5 Mhz. It then goes to a PAM ACPN-5704,then a demux (1732.5 / 2132.5 MHz.)before the antenna 2 switch.

PRX_HB is the receive signal. It is demultiplexed by filter FL11003.

DRX_HB is the same as for band 1

LTE as we all know is fully functional on this band.

LTE B4 PROVEN functional

LTE B4 TX 1710-1755 ANT 2 TX_MB1

LTE B4 RX 2110-2155 ANT 2 PRX_HB

LTE B4 DRX 2110-2155 ANT 6 DRX_HB

UMTS B4 TX 1710-1755 ANT 2

UMTS B4 RX 2110-2155 ANT 2

UMTS B4 DRX 2110-2155 ANT 6

TX_LB4 routes throug a ACPM-5505 PAM,then demuxes (836.50 / 881.50 MHz.) from PRX_LB3 and goes to antenna 2.

DRX_LB2 connects to an 881.5Mhz saw filter,then to antenna 3.

Band 5 LTE looks functional.

LTE B5 TX 824-849 ANT 2 TX_LB4

LTE B5 RX 869-894 ANT 2 PRX_LB3

LTE B5 DRX 869-894 ANT 3 DRX_LB2

UMTS B5 TX 824-849 ANT 2

UMTS B5 RX 869-894 ANT 2

UMTS B5 MRD 869-894 ANT 3

GSM 850 TX 824-849 ANT 2

GSM 850 RX 869-894 ANT 2

GSM 850 DRX 869-894 ANT 3

Band 7 LTE is not included. This is only used on the model sold in places like Canada and South America.

LTE B7 TX 2500-2570 ANT 1 TX_HB (Missing)

LTE B7 RX 2620-2690 ANT 1 PRX_HB (Missing)

LTE B7 DRX 2620-2690 ANT 6 DRX_HB(Missing)

TX_LB3 passaes through a 897.5Mhz saw filter before goingto the Quad GSM/LTE Band 1/8 amp then to antenna 2.

PRX_LB 2 goes directly to the switch and then antenna 2

DRX_LB1 has a 942.5Mhz saw filter before the switch,which then connects to antenna 6.(4?)

Band 8 LTE looks functional. Theres no reason this should not work if your carrier used LTE band 8,except that the modem software may not support it.

UMTS B8 TX 880-915 ANT 2 TX_LB3

UMTS B8 RX 925-960 ANT 2 PRX_LB2

UMTS B8 DRX 925-960 ANT 6 DRX_LB1

EGSM 900 TX 880-915 ANT 2 TX_LB3

EGSM 900 RX 925-960 ANT 2 PRX_LB2

EGSM 900 DRX 925-960 ANT 6 DRX_LB1

LTE B17 TX 704-716 TX_LB1 ANT 1(missing)

LTE B17 RX 734-746 PRX_LB1 ANT 1(missing)

LTE B17 DRX 734-746 DRX_LB2 ANT 3(missing)

This one is odd. Diversity receive for band 20 is shown on the schematic. But really,this is GSM_U850 DRX. The designation on the lines was just never changed. Its clear that 17/20 is was not one of the chosen bands.17 and 20 are typically another mutually exclusive pair.

LTE B20 TX 832-962 TX_LB1 ANT 1

LTE B20 PRX 791-821 PRX_LB1 ANT 1

LTE B20 DRX 791-821 DRX_LB2 ANT 3

GPS ANT 5

So hardware wise,the Nexus 4 should do LTE on bands 1,2,4,5,8.

Additionally,it might do Band 10,which is an extended superset of Band 4. Im not sure how the protocols work,in other words,whether it would simply restrict itself to Band 4,and its quite possible that it can go as wide as band 10. It would be interesting to test if anyone starts using it. Band 19 is a subset of band 5 so it should work,and band 18 is mostly contained within 5,but goes a little lower so it MIGHT work. 26 is close to 5,mostly contained within but goes a little lower,so it MIGHT work.Band 27 is even lower,still close,so it MIGHT work,but is less likely. Some of the TDD bands from 33-44 in theory would work as well,with the right software support. But that's the big issue on everything except whats working now. You would need a radio that supports it,or have to have enough understanding of the radio to graft it in,which for all I know might run afoul of the code signing of the modem firmware.

So,the design requirements ,to make it usable would be Band 2 of course,becuase Tmobile is transitioning its 2g and 3g over to band 2. AT&T runs 3g on bands 2 and 5. Tmobile is supposed to be able to roam on band 5. SO really,you need 2 and 5. Many tmobile markets still run 3g on band 4 though,so you need 4.In the Americas,outside of the US,the ones to have are bands 1,2,5,8 and 4. Exactly what the phone has. Bands 8 and 1 are common in Europe,and your pretty much out of available bands right there. So without LTE,the phone is pretty much good most places,or at least as many as you could hope for. With LTE,its only good a few places,and it would be a marketing nighmare to deal with.