UE Category is the set of information (parameters) that defines the maximum throughput for a UE. As LTE evolves, the length of UE category list gets longer and longer, and the interpretation of the category gets more complicated, you will need to go through many tables listed below to figure out the exact throughput capability of a UE. Followings are the list of tables you would need to go through for the detailed understanding. The tables reproduced here were captured between Release 12 and Release 14 of 36.306, and the list has kept growing since. The last section on this page sets them against 36.306 v19.3.0, so you can see which rows are missing and which table titles have changed.

• RRC Message that defines UE Category
• UE Category Tables
• 36.306 Table 4.1-1: Downlink physical layer parameter values set by the field ue-Category
• 36.306 Table 4.1-2: Uplink physical layer parameter values set by the field ue-Category
• 36.306 Table 4.1A-1: Downlink physical layer parameter values set by the field ue-CategoryDL
• 36.306 Table 4.1A-2: Uplink physical layer parameter values set by the field ue-CategoryUL
• 36.306 Table 4.1A-6: supported DL/UL Categories combinations set by the fields ue-CategoryDL and ue-CategoryUL
• 36.306 Table 4.1-3: Total layer 2 buffer sizes set by the field ue-Category
• 36.306 Table 4.1A-3: Total layer 2 buffer sizes set by the fields ue-CategoryDL and ue-CategoryUL
• 36.306 Table 4.1-4: Maximum number of bits of a MCH transport block received within a TTI set by the field ue-Category
• 36.306 Table 4.1-5: Half-duplex FDD operation type set by the field ue-Category
• 36.306 Table A-1: Maximum values for DL PDCP SDUs per TTI
• What 36.306 v19.3.0 adds to the tables above
• Reference

RRC Message that defines UE Category

The category that UE support is indicated in UE Capability Information message as shown below. Notice that ue-Category can specify only up to Cat 4.  The category higher than 4 should be assinged to another IE (Information Element) ue-Category-v1020. (Here we are having similar confusing IEs as in WCDMA/HSPA. So many different places to check to figure out exact category)

The block below is a decode taken from a protocol analyser, not text copied out of a specification. It records one UE Capability Information message as one network received it, so the values in it belong to that UE and none of them has been corrected against a later release.

Example 1 >

ueCapabilityInformation-r8
   ue-CapabilityRAT-ContainerList: 1 item
        Item 0
            UE-CapabilityRAT-Container
                rat-Type: eutra (0)
                ueCapabilityRAT-Container: ....
                    UE-EUTRA-Capability
                        accessStratumRelease: rel11 (3)
                        ue-Category: 4
                        ...
                        phyLayerParameters
                            .... 0... ue-TxAntennaSelectionSupported: False
                            .... .0.. ue-SpecificRefSigsSupported: False
                        rf-Parameters
                            supportedBandListEUTRA: 15 items...
                        measParameters
                            bandListEUTRA: 15 items
                                ...
                        featureGroupIndicators: ...
                            ...
                        interRAT-Parameters
                            ...
                        nonCriticalExtension
                            phyLayerParameters-v920
                                ...
                            interRAT-ParametersGERAN-v920
                                ...
                            interRAT-ParametersUTRA-v920
                                ...
                            csg-ProximityIndicationParameters-r9
                            neighCellSI-AcquisitionParameters-r9
                                ...
                            son-Parameters-r9
                                ...
                            nonCriticalExtension
                                lateNonCriticalExtension:...
                                    UE-EUTRA-Capability-v9a0-IEs
                                        featureGroupIndRel9Add-r9: ...
                                            ...
                                        fdd-Add-UE-EUTRA-Capabilities-r9
                                            phyLayerParameters-r9
                                                ...
                                            featureGroupIndicators-r9: ...
                                                ...
                                            featureGroupIndRel9Add-r9: ...
                                                ...
                                        tdd-Add-UE-EUTRA-Capabilities-r9
                                            phyLayerParameters-r9
                                                ...
                                            featureGroupIndicators-r9: ...
                                                ...
                                            featureGroupIndRel9Add-r9: ...
                                                ...
                                nonCriticalExtension
                                    ue-Category-v1020: 6
                                    phyLayerParameters-v1020
                                        multiClusterPUSCH-WithinCC-r10: supported (0)
                                        nonContiguousUL-RA-WithinCC-List-r10: ...
                                            ...
                                    rf-Parameters-v1020
                                        supportedBandCombination-r10: ...
                                            ...
                                    measParameters-v1020
                                        bandCombinationListEUTRA-r10: ...
                                            ...
                                    featureGroupIndRel10-r10: ...
                                        ...
                                    ue-BasedNetwPerfMeasParameters-r10
                                        ...
                                    nonCriticalExtension
                                        fdd-Add-UE-EUTRA-Capabilities-v1060
                                            featureGroupIndRel10-v1060: ...
                                                ...
                                        tdd-Add-UE-EUTRA-Capabilities-v1060
                                            featureGroupIndRel10-v1060: ...
                                                ...
                                        rf-Parameters-v1060
                                            supportedBandCombinationExt-r10: ...
                                                ...
                                        nonCriticalExtension
                                            nonCriticalExtension
                                                pdcp-Parameters-v1130
                                                phyLayerParameters-v1130
                                                    crs-InterfHandl-r11: supported (0)
                                                    tdd-SpecialSubframe-r11: supported (0)
                                                rf-Parameters-v1130
                                                    supportedBandCombination-v1130: ...
                                                        ...
                                                measParameters-v1130
                                                interRAT-ParametersCDMA2000-v1130
                                                otherParameters-r11
                                                nonCriticalExtension
                                                    ue-Category-v1170: 9
                                                    nonCriticalExtension

ue-Category cannot carry the answer on its own : the Release 8 field is an INTEGER (1..5), so the capture above writes 4 into it even though the UE is really Category 9.

Each release adds a field of its own : the same capture carries ue-Category-v1020 set to 6 and ue-Category-v1170 set to 9, each one sitting in the non-critical extension that its release opened.

The chain has to be read to the end : the category the UE really supports is the one in the deepest extension present, so a reader who stops at ue-Category reads this UE as Category 4.

The same message appears below in the ASN.1 tree form that the analyser also produces. This is the same capture seen from the other end: every field name carries its ASN.1 type and its value range, and the OPTIONAL:Exist marks say which optional fields the UE actually included.

Example 2 >


UE-EUTRA-Capability ::= SEQUENCE [11]
  +-accessStratumRelease ::= ENUMERATED [rel11]
  +-ue-Category ::= INTEGER (1..5) [4]
  +-pdcp-Parameters ::= SEQUENCE [0]
  +-phyLayerParameters ::= SEQUENCE
  +-rf-Parameters ::= SEQUENCE
  +-measParameters ::= SEQUENCE
  +-featureGroupIndicators ::= BIT STRING SIZE(32) OPTIONAL:Exist
  +-interRAT-Parameters ::= SEQUENCE [0000000]
  +-nonCriticalExtension ::= SEQUENCE [0001] OPTIONAL:Exist
    +-nonCriticalExtension ::= SEQUENCE [11] OPTIONAL:Exist
      +-lateNonCriticalExtension ::= OCTET STRING CONSTRAINTED
      +-nonCriticalExtension ::= SEQUENCE [111110101] OPTIONAL:Exist
        +-ue-Category-v1020 ::= INTEGER (6..8) [7] OPTIONAL:Exist
        +-phyLayerParameters-v1020 ::= SEQUENCE [0000011] OPTIONAL:Exist
        +-rf-Parameters-v1020 ::= SEQUENCE OPTIONAL:Exist
        +-measParameters-v1020 ::= SEQUENCE OPTIONAL:Exist
        +-featureGroupIndRel10-r10 ::= BIT STRING SIZE(32)
        +-interRAT-ParametersCDMA2000-v1020 ::= SEQUENCE OPTIONAL:Omit
        +-ue-BasedNetwPerfMeasParameters-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        +-interRAT-ParametersUTRA-TDD-v1020 ::= SEQUENCE OPTIONAL:Omit
        +-nonCriticalExtension ::= SEQUENCE [0011] OPTIONAL:Exist
          +-fdd-Add-UE-EUTRA-Capabilities-v1060 ::= SEQUENCE OPTIONAL:Omit
          +-tdd-Add-UE-EUTRA-Capabilities-v1060 ::= SEQUENCE OPTIONAL:Omit
          +-rf-Parameters-v1060 ::= SEQUENCE OPTIONAL:Exist
          +-nonCriticalExtension ::= SEQUENCE [01] OPTIONAL:Exist
            +-rf-Parameters-v1090 ::= SEQUENCE OPTIONAL:Omit
            +-nonCriticalExtension ::= SEQUENCE [1001] OPTIONAL:Exist
              +-nonCriticalExtension ::= SEQUENCE [011] OPTIONAL:Exist
                +-phyLayerParameters-v1170 ::= SEQUENCE OPTIONAL:Omit
                +-ue-Category-v1170 ::= INTEGER (9..10) [10] OPTIONAL:Exist
                +-nonCriticalExtension ::= SEQUENCE [10001] OPTIONAL:Exist
                  +-rf-Parameters-v1180 ::= SEQUENCE [100] OPTIONAL:Exist
                  +-mbms-Parameters-r11 ::= SEQUENCE OPTIONAL:Omit
                  +-fdd-Add-UE-EUTRA-Capabilities-v1180 ::= SEQUENCE OPTIONAL:Omit
                  +-tdd-Add-UE-EUTRA-Capabilities-v1180 ::= SEQUENCE OPTIONAL:Omit
                  +-nonCriticalExtension ::= SEQUENCE [101] OPTIONAL:Exist
                    +-ue-Category-v11a0 ::= INTEGER (11..12) [12] OPTIONAL:Exist
                    +-measParameters-v11a0 ::= SEQUENCE OPTIONAL:Omit
                    +-nonCriticalExtension ::= SEQUENCE [010011000000001] OPTIONAL:Exist
                      +-phyLayerParameters-v1250 ::= SEQUENCE OPTIONAL:Omit
                      +-rf-Parameters-v1250 ::= SEQUENCE [1000] OPTIONAL:Exist
                      +-rlc-Parameters-r12 ::= SEQUENCE OPTIONAL:Omit
                      +-ue-BasedNetwPerfMeasParameters-v1250 ::= SEQUENCE OPTIONAL:Omit
                      +-ue-CategoryDL-r12 ::= INTEGER (0..14) [12] OPTIONAL:Exist
                      +-ue-CategoryUL-r12 ::= INTEGER (0..13) [13] OPTIONAL:Exist
                      +-wlan-IW-Parameters-r12 ::= SEQUENCE OPTIONAL:Omit
                      +-measParameters-v1250 ::= SEQUENCE OPTIONAL:Omit
                      +-dc-Parameters-r12 ::= SEQUENCE OPTIONAL:Omit
                      +-mbms-Parameters-v1250 ::= SEQUENCE OPTIONAL:Omit
                      +-mac-Parameters-r12 ::= SEQUENCE OPTIONAL:Omit
                      +-fdd-Add-UE-EUTRA-Capabilities-v1250 ::= SEQUENCE OPTIONAL:Omit
                      +-tdd-Add-UE-EUTRA-Capabilities-v1250 ::= SEQUENCE OPTIONAL:Omit
                      +-sl-Parameters-r12 ::= SEQUENCE OPTIONAL:Omit
                      +-nonCriticalExtension ::= SEQUENCE [11] OPTIONAL:Exist
                        +-ue-CategoryDL-v1260 ::= INTEGER (15..16) [16] OPTIONAL:Exist
                        +-nonCriticalExtension ::= SEQUENCE [10] OPTIONAL:Exist
                          +-rf-Parameters-v1270 ::= SEQUENCE [10] OPTIONAL:Exist
                          +-nonCriticalExtension ::= SEQUENCE OPTIONAL:Omit

The ranges explain the chain : ue-Category is INTEGER (1..5), ue-Category-v1020 is (6..8), ue-Category-v1170 is (9..10) and ue-Category-v11a0 is (11..12). Each extension covers only the categories its own release added.

Release 12 splits the field in two : ue-CategoryDL-r12 and ue-CategoryUL-r12 appear further down the same tree, and from that point a UE states its downlink and its uplink capability separately.

The capture stops where its release stopped : the deepest category field in it is ue-CategoryDL-v1260, INTEGER (15..16). 36.331 v19.3.0 carries the chain on through ue-CategoryDL-v1310, -v1330, -v1350, -v1430, -v1450, -v1460 and -v1530, and the last of those is INTEGER (22..26).

UE Category Tables

36.306 defines the maximum throughput for each category as follows : The tables below fall into two groups. The first pair is indexed by the single ue-Category field, and the ones after it by the ue-CategoryDL and ue-CategoryUL pair that Release 12 introduced. Each table carries its own version stamp, and the stamps are not all the same.

Note : Following throughput does not make difference about the number of Carriers. When you are talking about Categories about Carrier Aggregation throughput, you would be clear on whether you are talking about the category for each component carrier or categories of aggregated carriers.

This tables tells you only about the maximum throughput, it doesn't tell in detail about how you achieve it. Many people tries to associate this table to a specific MIMO configuration or Carrier Aggregation(CA) configuration. But there is no direction connection between this table and MIMO/CA condition.

The table below is the one that ue-Category points into. It gives four numbers per category: the transport block bits a UE can receive in one TTI, the largest single transport block, the soft channel bit budget behind the HARQ buffer, and the number of spatial layers.

< 36.306 v12.6 Table 4.1-1: Downlink physical layer parameter values set by the field ue-Category >

Category 4 is the familiar 150 Mbps : 150 752 bits per TTI, carried as a single 75 376 bit transport block on each of two layers.

Category 8 is the top of this table : 2 998 560 bits per TTI over eight layers, with 35 982 720 soft channel bits behind it.

256QAM arrives with Categories 11 and 12 : the picture opens a second transport block row for them, and the soft channel bit count does not move with it.

The uplink half of the same pair is much shorter. Before Release 12 only three things varied from one category to the next. They are how many bits the UE can send in a TTI, how large a single transport block may be, and whether it may use 64QAM.

< 36.306 v12.6 Table 4.1-2: Uplink physical layer parameter values set by the field ue-Category >

Only two categories admit 64QAM in the uplink : Category 5 and Category 8 are the only Yes rows in the picture, and every other category is held to 16QAM.

Note 1 : The number shown in this table is the number of bits that can be transmitted in 1 TTI (1 ms). So you have to multiply this number by 1000 to get the rate in 'bps'. For example, Table 4.1-1 Category 3 says 102048. If you convert this number into bps, it is 102048 x 1000 = 102,048,000 bps.

Note 2 : You should be very careful when you talk about the throughput in Kbps, Mbps unit. A lot of people do the conversion by dividing the number by 1000, 1000000. But in digital theory (especially in computer world) 1 Kbps is 2^10 bits and 1 Mbps is 2^20 bits. When the number is small, you don't see much difference, however when the number is very big, the difference between the two different conversion would give you huge difference. For bit rates, though, the usual convention in telecom is decimal. So 1 kbps is 1000 bit/s and 1 Mbps is 1 000 000 bit/s. The binary 2¹⁰ and 2²⁰ belong to memory sizes, such as a buffer size in bytes.

Note 3 : The number shows in this table is based on the assumption that all the DL/UL TTI carries only user data (U-Plane Data), but in really you cannot allocate 100% of resources for user data only. There should be a certain portion of overhead (like SIBs, MAC CE, Signaling etc). So real throughput you get will be less than the one listed in this table.

In Release 12, there are other categories in which we can specify DL category and UL category separately as shown below.

The decode below comes from a UE that fills in the Release 12 fields. It is the same message type as the two above, and it is left exactly as it was captured.

ueCapabilityInformation-r8
   ue-CapabilityRAT-ContainerList: 1 item
        Item 0
            UE-CapabilityRAT-Container
                rat-Type: eutra (0)
                ueCapabilityRAT-Container: ....
                    UE-EUTRA-Capability
                        accessStratumRelease: ...
                        ue-Category: 4
                        ...
                        nonCriticalExtension
                            ...
                            nonCriticalExtension
                                lateNonCriticalExtension:...
                                    ....
                                nonCriticalExtension
                                    ue-Category-v1020: 6
                                    ...
                                    nonCriticalExtension
                                        ...
                                        nonCriticalExtension
                                            nonCriticalExtension
                                                ....
                                                nonCriticalExtension
                                                    ue-Category-v1170: 9
                                                    nonCriticalExtension
                                                       phyLayerParameters-v1250
                                                       rf-Parameters-v1250
                                                       rlc-Parameters-r12
                                                       ue-BasedNetwPerMeasParameters-v1250
                                                       ue-CategoryDL-r12  : 14
                                                       ue-CategoryUL-r12  : 13
                                                       wlan-IW-Parameters-r12
                                                       measParameters-r1250
                                                       dc-Parameters-r12
                                                       mbms-Parameters-r12
                                                       mac-Parameters-r12
                                                       fdd-Add-UE-EUTRA-Capabilities-v1250
                                                       fdd-Add-UE-EUTRA-Capabilities-v1250
                                                       sl-Parameters-r12
                                                       nonCriticalExtension

Two numbers instead of one : the capture carries ue-CategoryDL-r12 set to 14 and ue-CategoryUL-r12 set to 13, while the older ue-Category, ue-Category-v1020 and ue-Category-v1170 fields are still present with 4, 6 and 9 in them.

The old fields are not dropped : 36.306 clause 4.1A names the combinations a UE is allowed to signal and also says which plain UE Categories it has to indicate in addition, which is why both sets travel together.

<  36.306 v14.5 - Table 4.1A-1: Downlink physical layer parameter values set by the field ue-CategoryDL >

Release 12 gives the uplink a category list of its own, and the picture below is the uplink counterpart of the table above it. The stamp on it is v13.4, one release earlier than the v14.5 stamp on the table above it.

< 36.306 v13.4 - Table 4.1A-2: Uplink physical layer parameter values set by the field ue-CategoryUL >

The low categories are the machine-type ones : UL Category M1 and UL Category 0 both sit at 1 000 bits per TTI, against UL Category 14 at 9 585 664 bits.

Not every downlink category may be paired with every uplink category. The three pictures below carry the table that lists the pairs a UE is allowed to signal, together with the plain UE Category it has to indicate alongside them.

< 36.306 v12.6 - Table 4.1A-6: supported DL/UL Categories combinations set by the fields ue-CategoryDL and ue-CategoryUL and UE categories to be indicated >

One pair is given a bandwidth of its own : DL Category M1 with UL Category M1 is written as 1.4 MHz, and every other row says the maximum channel bandwidth follows the band, as specified per band in 36.101.

The right hand column is the compatibility answer : it names the plain UE Category the UE must also send, so an eNB that reads only ue-Category still gets a usable number out of the message.

To implement the specified UE category, we need to consider various factors along the full stack. Followings are some parameters above Physical layer.

Throughput on its own does not size a UE. The layer 2 buffer has to hold what the HARQ and reordering windows have in flight, and 36.306 sets that per category as well.

< 36.306 v12.6 Table 4.1-3: Total layer 2 buffer sizes set by the field ue-Category >

The unit changes here : this table is stated in bytes, while every transport block row above it is stated in bits, so the two sets of numbers are not comparable as they stand.

The Release 13 version of the same table is indexed by the DL and UL category pair rather than by a single category, which is what the split into ue-CategoryDL and ue-CategoryUL forces.

< 36.306 v13.4 Table 4.1A-3: Total layer 2 buffer sizes set by the fields ue-CategoryDL and ue-CategoryUL >

The pair indexes the row : DL Category 17 with UL Category 14 is given 330 000 000 bytes, and the picture adds a second column for a UE that also supports split bearers.

A UE that receives MBMS over MBSFN needs a separate number, because the MCH transport block is not the DL-SCH one and it is not covered by the tables above.

< 36.306 v12.6 Table 4.1-4: Maximum number of bits of a MCH transport block received within a TTI set by the field ue-Category for an MBMS capable UE >

Half-duplex FDD is the last thing the category settles. A half-duplex UE cannot transmit and receive at the same time, and the operation type says how the guard period between the two is taken.

< 36.306 v12.6 Table 4.1-5: Half-duplex FDD operation type set by the field ue-Category for a half-duplex FDD capable UE >

Every category in the table above is Type A : the distinction only starts to earn its keep in the ue-CategoryDL version of the table, where the machine-type categories are Type B instead.

Following table represents the max number of PDCP SDUs for each Category. I think this is just enough to achieve the phy/mac max throughput (Table 4.1-1) when the packet size of user data (e.g, IP data) is very large. If the packet size is very small, you would not achieve the maximum throughput at IP level with this number of PDCP SDUs.

The last table is informative. It does not set a limit the UE has to meet; it gives the PDCP SDU count a designer can dimension for, and 36.306 introduces it as a help to the dimensioning of the UE design.

< 36.306 v14.5 Table A-1: Maximum values for DL PDCP SDUs per TTI >

What 36.306 v19.3.0 adds to the tables above

Every table above carries its own version stamp, and not one of them is current. 36.306 has reached v19.3.0, and the category list has been extended in almost every release since Release 14. This section says what has changed, so the tables above can be read for what they are, which is a snapshot rather than the present state.

The downlink list now ends at 26 : Table 4.1A-1 of v19.3.0 runs M1, M2, 0, 1bis, 4, 6, 7 and then 9 through 26. The copy on this page stops at DL Category 20.

The uplink list ends at 26 as well : Table 4.1A-2 runs M1, M2, 0, 1bis, 3, 5, 7, 8 and then 13 through 26, against a copy here that stops at UL Category 15.

1024QAM has been added to the downlink table : DL Category 26 is given 502 624 bits for an eight layer 1024QAM transport block, beside 391 656 bits for 256QAM and 299 856 bits for 64QAM. The v14.5 copy above carries 256QAM rows and no 1024QAM ones.

The uplink table has gained a second modulation column : v19.3.0 asks for 64QAM support and 256QAM support separately, and UL Category 26 answers Yes to both at 844 224 bits per TTI.

Table 4.1A-6 has been split in two : v19.3.0 keeps 4.1A-6 for UEs other than Category M and adds Table 4.1A-7 for UEs of Category M. Both titles are longer than the one captioned above, because maximum UE channel bandwidth is now named in them.

Table A-1 has been extended too : the informative PDCP SDU table now runs to DL Category 26 at 600 SDUs per TTI, where the copy above stops at DL Category 20 and 360.

The extension chain in 36.331 is much longer now : ue-CategoryDL carries on past v1260 with v1310, v1330, v1350, v1430, v1450, v1460 and v1530, and ue-CategoryUL with v1310, v1340, v1350, v1430, v1430b and v1530. The last entry on each side is INTEGER (22..26).

Two whole families are missing from this page : clause 4.1B defines ue-CategorySL-C-RX, ue-CategorySL-C-TX and ue-CategorySL-D for sidelink, with Tables 4.1B-1, 4.1B-2 and 4.1B-3 behind them, and clause 4.1C defines ue-Category-NB for NB-IoT, with Tables 4.1C-1, 4.1C-2, 4.1C-3 and 4.1C-5.

Two downlink tables are missing as well : Table 4.1A-4 gives the MCH transport block limit for ue-CategoryDL and Table 4.1A-5 gives its half-duplex FDD type. They are the ue-CategoryDL counterparts of Table 4.1-4 and Table 4.1-5 above.

Reference

The specifications below are the ones this page reads from. 36.306 and 36.331 were both resolved at v19.3.0, which is the latest published version at the time of writing.

• 3GPP TS 36.306 v19.3.0, E-UTRA User Equipment radio access capabilities. Clause 4.1 for ue-Category, clause 4.1A for ue-CategoryDL and ue-CategoryUL, clause 4.1B for the sidelink categories, clause 4.1C for ue-Category-NB, and Annex A for Table A-1.
• 3GPP TS 36.331 v19.3.0, E-UTRA Radio Resource Control protocol specification. UE-EUTRA-Capability and the ue-Category extension chain.
• 3GPP TS 36.101, E-UTRA User Equipment radio transmission and reception. The per band channel bandwidth that Table 4.1A-6 defers to.